My project started with wanting a clean clear tone that I couldn't get with humbuckers. I always wanted to build a guitar but figured it would be cheaper to rebuild a beater guitar with premium parts. A Fender "Custom Vibe" Telecaster sells for $400 new so I used $400 as my budget. I learned just enough electonics in the Navy, decades ago, to be dangerous.
I figure old banged up guitars are the ones that got played a lot and old pretty guitars don't get played because there is something wrong with the neck. Mine is a scratched up and chipped like it gigged every night. I didn't mind opening it up several times to try different things. I kept the strings long so I could keep reusing them. You'll want a good solder sucker because you'll need one if you want to redo anything.
I'll replace the bridge one day, but that will require some routing so I'm in no hurry. I have a rich rewarding tone from a guitar with a great neck and look forward to playing, so my I recommendation to you matonanjin is to watch a lot of videos and when you feel ready, go for it. Here are some YouTube resources I used:
Breja ToneWorks https://www.youtube.com/user/BrejaToneWorks
Dave's World of Fun Stuff https://www.youtube.com/user/davey4557
soldering video https://texasbluesalley.com/woodshed/free/how-to-replace-strat-pickups
John Cooper how, what and why https://www.youtube.com/user/johnplanetz/playlists