You could get a YYJ Dark Magic. Comes with 2 bearings so it takes you from beginner to master. Polyester string is the best, but you might want to try 50% cotton and 50% polyester. Your choice!
Don’t stress about practicing, because yoyoing is about having fun, not trying to be the next yoyo champ or something. Sure winning contests is great, but just have fun!
Try not to make my mistake which was try a trick, get it once, then move on thinking you mastered that trick because you didn’t. Practice and practice until that trick is really mastered. Some tricks you Need to know are trapeze, double or nothing, one and a half mount, and sleeper of course. Andre’s tutorials on this site are great, but later on some tricks get really difficult, so don’t be afraid to ask about a trick because there is a trick section on the forum. Also, if you get a friend to yoyo, its a lot more fun, and you could have a contest to see who can learn a trick faster.
There are many different styles of yoyoing. 1a is probably the most popular. Its just where you yoyo with the string attached to your finger. 2a I believe is looping, with 2 yoyos, one on each hand. I’m not so sure what 3a is, but 4a is offstring, usually played with a bigger yoyo and the string is attached to your finger but not the yoyo. 5a is just like 1a but instead of the string attached to your finger, its attached to a counter-weight. Just pick what you think will be the most interesting, but most people start with 1a. The YYJ Dark Magic is the classic butterfly shape, but there are many more shapes.