GTO WIZARD is free to look at ranges at multiple stack depths- MTT requires you to stack protect at points in the MTT so your Villains will be folding more often taking advantage of those extra folds is a good spot to study--Bet sizing in MTT is not the same as CASH bet size strength is often based more on V stack than pot size at lower stacks.
Start with small tournaments — micro-stakes or freerolls will help you get used to the tournament structure, blinds, and stages of play without taking serious risks.