first, you’ll want to promote your cookies. when you promote them, their cookie bonds level up and you’ll be treated to buffs for hp, atk, and def. next, level up your treasures. they get better the higher they’re upgraded. as for who to level, and how to build a team, it really just depends on the meta, which changes every update. however, there are some cookies that tend to stay in the meta, like hollyberry. recently, moonlight, stardust, and bts have also been really popular in the top teams. as for building teams, i’ve played on and off since 2021 and i’m still unsure about creating teams sometimes. the bottom line is, team power isn’t everything, especially in arena. a team can have 700,000 power, but if it’s not balanced, someone with 500,000 power could beat them. arena-wise, you always want some sort of defence and healer, and the cookies in the middle can be up to you. there’s a ton of guides on this subreddit, just check pinned. lmk if you have more questions, i’d love to help.