I’ve been using WeMod (think Steam but for trainers/cheats) since it was released years ago. I was too poor to buy a sub to help the devs, but I contributed what I could.
Fast-forward to today, the app is full of ads and limits you to 2 hours before disabling itself unless you pay up. The enshitification is so far beyond the pale that I immediately uninstalled it and will never use it again.
A pretty reliable source (also for new trainers) is flingtrainer.com (there is also wemod bullshit, but at least the individual trainers are still downloadable). Never had any problems with them, they also work reliably on Linux.
Apart from that, gamecopyworld is your friend.