No drawing tablets are touch screen?? though. Except for Cintiq but those are like over 1000 dollars.
Basically, tablets are things you use to draw digitally on your computer. Every tablet comes with a pen and a few nibs. Nibs are things you place inside of your tablet pen, and it allows you to draw. Tablets come with extra nibs because nibs slowly shorten over time. (Like really slowly. I've had my current tablet for nearly 2 years, and I haven't replaced the nib once. I mean, I have to test it out a couple times, but all of them are still at a pretty nice length.)
The way that they work is kind of confusing at first though and takes some getting used to. You look up at your screen while drawing with the tablet which is on your desk??? Like, imagine drawing on a piece of paper and nothing shows up on the paper, but it shows up on your computer screen. It sounds pretty weird tbh but it's not too hard to get used to.
The most popular company for tablets is Wacom. The company's tablets and other products are really nice!
The only other thing is that you'll need to download a better program than Paint and a less difficult program than Photoshop, and you'll need to download some drives. Paint Tool Sai is probably one of the best programs out there, but it's not available for Mac and it's not free. I'm not gonna get into too much detail here though because you're asking about tablets and not drawing programs. hh