What To Buy?

It really just depends on which one you like better and how bug your hands are. I have really small hands so I started with a soprano, and got others. I still play my soprano all the tine though. (It's my favorite)

Sopranos are the typical kind of ukulele, they're really small so they might not be the best if you have larger hands or if you're just more comfortable with something larger to hold.

I have a Concert which is basically just bigger and slightly louder. It's honestly the perfect size, not too small but still sounds like your typical ukulele.

Tenors are bigger and have a deeper sound to them. I think they sound really nice, but I've never played one personally.

Baritones are the biggest and deepest. They're about the size of a guitar. They're tuned differently than the others, so you would have to find music specifically for a baritone uke.