Fps games can be a tough undertaking for a beginner. That being said though, I made a simple complete FPS space game in a single day after following the "Create with Code" course on Unity Learn. It really gives you a good understanding of all the primary game dev aspects by having you code 5 game prototypes from scratch, then fixing 5 bugged/broken games, and finally creating you own project without anyone holding your hand. You will be quizzed along the way and I definitely suggest you(and everyone) check it out if you want to make your own project of any kind.

Okay, then you can clone the project and edit what you don't like about it. Like, Transform.translate, Velocity, position, you know the ones. Just don't take too long experimenting. You're better served finding another easy FPS tutorial.

for exemple the movment by force feels off

i have done the make your first game tutorial it was kinda simple but

As the creators of Unity said, game dev should be undertaken little by little. This is the very first of the little pieces, and the feeling of accomplishment you get from every little piece is important for the mindset you'll have when you become an expert. If you're ready for more, however, Brackey's is the best I can think of on youtube.