I can’t use mods

So I downloaded a bunch of mods I really liked. I watched tons of videos of how to download mods In Minecraft IOS. but they didn’t work. It says installed and then when i create a new world and try to find it. I saw you need to make them (the blocks and other Add-ons) But with some other mods/Add-ons I couldn’t download it. But other people with the same version could. Sorry if you don’t understand but I really want mods cause it makes the game better to play. Stay safe : )