No professionals use point-and-shoots. I mean, yeah, they probably have one but the pix you see on magazine covers were NOT shot with point-and-shoots. To get that kind of quality, with that kind of flexibility to cover aaaaaall those situations, you gotta get a real camera. That would be a digital single-lens-reflex camera. DSLR, or dSLR or these days, just call the damn thing an SLR. Who shoots film any more, anyway?
So what's the big deal about an SLR? Well, image quality, speed and manual controls. The sensor is far bigger than the one in your cellphone, and that makes a difference. It means sharper pix and less digital noise in dark areas. It means better saturation, better contrast, less artifacts, everything. I know you've gotten some great pix with your point-and-shoot and your cellphone, but probably the light was good. When it isn't, you'll see your success rate plummet. Speed: there's no shutter lag. You push the button and you take the picture. That's huge when shooting sports, live performances and even posed portraits--you catch the expression you see, right there. Manual controls: yes, I know the full-auto modes do a great job, but only under certain conditions. Take a look at my night landscapes, my band pictures--all done in manual mode. Most of my portrait shots, too. Are you convinced yet? You need an SLR to get great pix consistently.
But which SLR? I'm glad you asked. First, I gotta admit I'm a Canon guy. I'm told Nikon makes a decent camera, but I couldn't speak to that. As for the others, why would you bother? Go with Canon or Nikon because you can continue to upgrade and all your old stuff will be compatible. The decision you make now will likely commit you for life, because at some point it'll be too damn expensive to toss all your Canon gear and switch to Nikon. My best advice--and this may sound facetious but it's not--is to buy whatever your closest camera buddy has, so you can ask all those stupid questions you're going to have. If said buddy is a Nikon guy he's not going to be much help with the menu structure on your Canon.
But for now, I'm your camera buddy and I shoot Canon. They make three lines of DSLRs, and they're all great. It really comes down to how much money you want to blow. Yes, the 1DX is the best and it's what all the pro's use, but the cheap Rebel line still takes great shots. Assuming you can take a great shot, that is. As of January 2017 you can get a T6 plus a couple of lenses for under $500 on sale. That's a great place to start. The two lenses will cover a good range from fairly wide-angle to a pretty good zoom. The camera body has a good sensor and processor in it; the battery life is good, the various shooting modes are easy to set, you can mount an external flash on it, you can set it on a tripod and use a cable release--all that good stuff that you're going to want to do as you progress to better and better photos. The body-only costs around $3250--not that I want you to buy the body-only, but remember that for reference. There are variants of this line--the T6i, for example, but I don't know anything about them so you'll have to go elsewhere for advice on which to buy.
The next step up is the Canon 80D. This intermediate range is aimed a people like me who think that spending more will result in better pictures when really it's my composition that needs the attention. This line generally has a newer, more powerful processor than the Rebels, maybe a better sensor and, most importantly, it has a spiffy little window on the top with all sorts of buttons and displays for controlling the stuff you need in a hurry. I find those make a huge difference when you move out of full-auto. Body-only runs around $1000, so it's considerably more expensive. It'll use the same lenses as the Rebel (or any Canon SLR) but if you're buying this body you need to be thinking about better lenses, too. Urrgh.
The next step up is the 7D Mk II. It's a credible sports camera and what I use now for birds. Fast, accurate tracking, great image quality and an all around great camera. If you have the money but don't want to commit to a full-frame camera (which costs more and almost demands more lenses), this is the one to buy.
The next step brings you to full-frame cameras like the 6D, 5D Mk IV and 1DX. Full-frame means the sensor is the same size as the old 35mm film--about 40% larger than the sensors in the cheaper cameras. That means less digital noise and better image quality. People rave about the 6D. It doesn't have quite the controls and speed of the 5D, but it's a whole lot cheaper and takes great pictures. About $2200 these days. However. . .I like my faster and more capable Canon 5D Mk IV for landscapes and portraits and shooting bands in dark rooms; in fact, I really couldn't do those things very well with a crop-sensor camera. Body-only runs about $3500, and that's getting well into the pro-camera range. The top Canon cameras are the 1D in it's various flavors, and now the body-only costs between $6000 and $7000. Ouch. The other cameras I've mentioned have smaller sensors, and point-and-shoots have even smaller sensors. Size matters: not just pixels, but the whole surface area of the sensor. The bigger the sensor, the less digital noise, the better you can shoot in the dark, and the better the images look. But this is all well beyond what you need to be worrying about if you're reading this. If you're ready for full-frames, google some better advice.
Yes, that's "lenses" plural. What's the point of having a camera like this if you don't have a bag full of lenses? If you have some coin to toss around--and in particular if you bought the 7D or 5D Mk III--you should spend it on Canon's pro line of lenses. They are sharp, with better colors and less distortion and smarter auto-focus and on and on. And they help you get lots and lots of bonus points on your credit cards. Here are some of the ones I like. Well, really I'd like to own them all but these are a good starting point. I have to confess a preference for zoom lenses when I'm not shooting bands in dark bars. Yeah, maybe there's better sharpness on a "prime" lens but who cares? These are already godlike. And waaaaay convenient.
Canon actually has two levels of L lenses. The really pricey stuff has low f/stops like 2.8. The cheap stuff--remember "cheap" is a relative term--only stops down to f/4. The 24-105 is an f/4 lens and hence cheaper (and lighter) than the excellent 24-70mm f/2.8 L lens. It's also very, very versatile. If you're only bringing one lens, bring this one. Stopping down to f/4 will give you decent bokeh on a portrait, and the flexibility of the zoom range makes it really handy. Remember that for landscapes you're going to be shooting on a tripod anyway (right?) so you don't need a "fast" lens--you'll be shooting at an f/stop like 16 or 22. With Image Stabilizing, you can handhold a shot down to fairly low speeds. And it weighs less than the 24-70.
This is my favorite lens of all time. I love this lens so much, I wish I had a wife so I could leave her for it. It's sharp and clear and fast-focusing and does magic things to a picture. Most of my horse racing pictures, most of my band pictures and most of my portraits were taken with this lens. Yeah, it's heavy and expensive but it's wonderful. Go buy one right now.
More rational people might consider this lens. It's lighter, but still has great glass and image stabilizing and fast focusing. It's a great lens and costs about half what the 2.8 version does. Yeah, it only stops down to f/4 but for the price difference it's a great alternative.
Since I shoot all my landscapes with my full-frame camera, this is my go-to lens for anything wide. It's also handy up close to the stage in a dark bar. But as I mentioned above, when you're shooting landscapes you generally want lots of depth-of-field, so the slower f/4 version is just fine--and it's image-stabilized.