You can start by looking up your name on major search engines and delete social accounts that are yours, and for the people search websites some of them have opt outs but most are really annoying and don’t comply (in my experience)
Consider using a privacy respecting browser like Firefox with the extension uBlock origin. Keep it to a max of two other extensions because it makes your browser more identifiable.
Consider using open source software over closed source software (just because it’s open source doesn’t mean it’s always safe)
For email I use proton mail and I’ve been very happy with it along with there other stuff.
As some other people have mentioned, self hosting is a good option if you have the time for it, and a spare computer laying around.
In addition to the other comment, for places and things where you cannot delete yourself, or where you cannot avoid tracking even if you do, you can use stuff like , which sends out random queries to hide your actual interactions. Got my interest profile on Google completely generic after a few months.
I would look to someone such as Michael Bazzell, he has a great podcast "the privacy, security and OSINT show. He offers loads of information on privacy and can advise on what you are looking for. Check his website :
https://inteltechniques.com/index.html