|⦵ Gary Bush Venture-Lieutenant|
The tiers are 1 to 4, not 1 to 3.
Unless you have tickets for the special 1-99, you can play a level 1 in a 1-4 adventure.
The GM will calculate the APL (average party level) to determine how challenging the adventure will be. If others at the table are playing 3rd and 4th level characters you could be pulled into a high tier.
If this happens, you can play a 4th level pregen that you can apply to you created character.
What adventures do you have tickets for?
You get 1 XP for each adventure and gain a new level every three XP earned. It sounds like you have not download the free guide to Starfinder Society.