I wonder if it's possible to move the game files from one pc to another and still have all gaming levels and achivements saved

I'm going to buy a new better pc and don't want to start the game all over again

Yes.

STEAM keeps track of your achivements and saves. Simply reconnecting your new PC to your STEAM account should do all that.

However, it won't save any mods you didn't download from the workshop. If you have those, you'll need to move them from your old PC to the new one, and it may be a good idea to do the same with your saves, just in case you've been playing a lot in offline mode recently.

Also, it might be cheaper to simply upgrade your PC than to outright buy a new one (unless, of course, multiple components are completely obsolete). You certainly won't have to worry about transferring your data unless the hard drive explodes. If you don't know how to build/upgrade your PC, it's not too hard learn. Typically, it just boils down to insert component X into slot X, and run the installer on the disk the part came with.

Yes you can move it, as long you re-register with your personal account. Then you will lose nothing!