What size should my first hoop be?
Here is an amazing link on hoop size and tubing type!
What’s the difference between 3 / 4 and 5 / 8 tubing diameter?
The most commonly used is 3/4 among hoopers. It is slightly larger/heavier, more durable (less likely to crack), and less reactive than the 5/8 tubing . 5/8 is used mostly by experienced hoopers because it is thinner and super reactive . But it is all personal preference!