1. Use a password manager
2. Use #Matrix
3. Use #Tor
4. Use #privacy email addresses
5. Buy things with #cash, #Monero, #Bitcoin or prepaid credit cards

Pretty much in that order. If you want to dive into #VPNs, #FIDO2 #hardware, #passkeys, #Qubes, firewalls, burner phones, #VoIP lines, freezing your credit reports, and the like, that's cool, but get the basics down first.