Who do I pick?
Pick whoever you want.
Character choice is obviously important, but sticking with someone you like is far more sustainable than taking an early tier list as gospel. Modern Fighting Games are as such that it's nigh impossible to lose on character select, and more importantly: Character strength is most relevant at the highest level of play.
Hop in game and experiment. Press buttons in Training Mode and see what feels good to do. Even if Street Fighter 6 is your first fighting game, you might already ideas of what archetype you're looking for.
- Do you prefer quick, nimble characters?
- Or lumbering, hard-hitting beasts?
- Would you like to manage a separate resource while you fight?
- Or keep it simple?
- Do you love projectiles?
- Or think zoning is cheating?