Yrtti: I hope you don't use any form of social media, google or anything they own, M$ related stuff, Skype, Amazon, certain Anti-Virus programs etc.
it's so easy to:
-use a bogus social media account on any of the current providers (with abosolutely none of your real data given);
-privately and anonymously search with
Disconnect Search or their browser
extension -use a per-site-firewall-like-blocker and configure it to any of your liking:
uBlock Origin -use a private, secure and encrypted web-email client like
ProtonMail So far, all of these are totally free, zero cents invested.
If you want even more, then buy a private VPN service using bitcoins. this way, they won't know your IP and even a court order could not force them to give away your real IP if you choose your VPN wisely among those who don't keep any logs whatsoever ... and with bitcoin payment they could not trace your real identity.
You also could buy a SIM card for your phone not tied to your data. So easy.
etc
If one really wants he can still be 100% private on the internet.