Save progress in each character

I want it so that when you play with a character and complete stuff and then create a new character, that it will reset everything in the new character but still save the progress in the first character, so you can have one character to play with friends and on to play alone.

You need to learn how to do manual saves of the save files. Then you play one character and when done, manual save that character where they are at in game.
Then start new game, new character and save that game when done. Delete game save files and load first character save files back to play where you left off with that character.

It is doable but it is also tedious with a lot of room to screw everything up. You have to remember to save when you exit the game every time. But if you crash and lose everything you have back up files.