Welcome
1) tournaments and match play challenge- stroke play free events are available every week and also monthly tournaments. There are also premium stroke play events if you scroll down a little further, but you are not elligible for all since they are based on tiers. Match Play Challenge are match play can join or create, you can wager credits against other players. ***Depending on your state of residence some of these options may not be open to you. The FAQs over here ======> are your best best friend.
2)The starting rank for pro, I assume you mean starting score. That is up in the air was WGT keeps it secret to prevent sandbagging for one. Your best bet, practice, play and post your scores (play ranked rounds to completion). Your score will accurately reflect your rank.
Great reason for wanting to know score for pro though. As you posted certain clubs are only available to that tier. So its up to you to wait or buy clubs as amateur. Many people make pro with starter equipment, its not hard once you figure out the game (once again use the FAQs ============>, the putting and chipping tips are outstanding and can solve all your short game woes taht we all had in the beginning)
Best of luck, and dont forget, practice is important, try different shots out. you have 10 strokes per hole in practice mode, use all of them to try different shots, especially chip vs. pitch vs flop options. The putting FAW is excellent as well, and these FAQs are from experienced PLAYERS.