It’s fun if you could get your favourite vehicle even though you can’t play it in multiplayer.
There will never be a trainer for War Thunder.
Trainers are for offline, single player games. War Thunder is an online, multiplayer game.
It is not possible to make trainers for online games for technical reasons. There are also moral and legal reasons as to why no trainer will ever exist for it.
Anyone who claims they have cheats for War Thunder, or any MMO game for that matter, is a scammer trying to steal your money or account password.