I'm closer to the average user than someone who has built a fortress. I use Firefox with ublock, ghostery, and privacy badger. I use the free tier of proton vpn. I run avast daily and malwarebytes weekly.
I think that I should already be close to best practices but I'm not sure how changing OS will affect that. I'm not really worried about being targeted for anything. I don't think that I really do much risky beyond the occasional torrent or downloading a patch for a game. I get games primarily from gog, don't open strange emails or click strange links, and use a password manager to generate secure passwords. One of the things that I'm most unsure about is keeping everything updated. Microsoft manages keeping everything updated for the most part on Windows and the last time I needed to find a driver anywhere except from Microsoft it came on a 3.5" floppy.
I use my computer primarily for single player gaming, discord, and fediverse sites. I need a spreadsheet and word processer, I use open office for that right now. I do financial and work related things on a different device.
I used to work for a German chemical manufacturer. One of the things they highlighted in their history is that in the lead up to WW2 they moved their headquarters and German factories to the UK and started making aircraft paint for the RAF. Overall they were a good company to work for.