If you're F2P and Adventure Rank 20 World Level 1, stop doing quests and only do Daily Commissions as main AR EXP, mini-Mob Bosses for materials, and use Resin for Bosses in order to get Ascension materials to stockpile them. You should be able to get full boss materials for 2 ascensions after lvl 40 per character for a full party before AR25/World Level 2 (x12 Boss Materials needed for a lvl 40 to get 2 ascensions after). Because if you rush World Levels you won't do jack shit damage and you'll be behind doing 60 min boss fights for 1 material.
Focus on 2 main characters ideally 1 DPS, 1 Healer