gonna try to add info that hasnt already been said in case it helps: passes regenerate every few hours or so. and now if you run out you can watch ads for more passes. when i first started playing i didnt understand the concept. so you can get free passes if you wait.
you dont need gems but they do enhance the game if you want. and in the episode-written stories, they do sometimes make you feel bad if you dont use them lol but try to ignore that.
also, one time i got a deal of like 10 passes for only 50 cents or a dollar or something, and also a similar deal for gems. and i remember it being a really great deal so if you want to save money then wait for a deal like that to show up.
also, idk if this went the same way for everyone, but when i first started playing i only got 2 passes before i had to wait for them to refill again. now i get 4 at a time which makes a huge difference and i feel like i can actually read a decent amount of content for free without waiting. so, dont get discouraged if it only gives you 2 at first!