Depending on which version you have of the game, there's an option to rename your character in the main menu.
I think that fixes the problem you're having. If not, you can download the Android patch fix (even if you're not playing on Android) and apply it, and then the option to rename your MC should appear on the main menu.
Alternatively if you play through the first day again (holding CTRL to skip through seen dialogue on PC) you can get to the part where you name your character super quickly, and that should also fix the issue, I think.