Organizing a messy developer’s system

Hi, all. I'm moving to a new laptop at work and would like to prevent technical debt by not just dumping everything into an "old" folder and starting fresh (I'd later be looking for things forever). Due to my own bad practices, I am now full of remorse for failing to stick to my file management scheme more strictly, and am turning to you for help. What are some useful tricks in how you've approached file cleanup on a work machine with many disorganized projects? Ancient files with unknown uses, duplicates of what should have been packaged and reused, minor tweaks on entire projects, inconsistent naming conventions… I'm ashamed to admit I have it all and likely more. Appreciate any advice you can offer, am trying to do better 🙂