Yes, this. As long as your router lets you changed your dns, then its simple, just point to the internal ip of your dns server and 'bobs your uncle'. Technitium dns, adguard home, and pihole are all good options to play around with; each with pros and cons but i find pihole is the easiest, then adguard home, then technitium dns. Play around with them find your fav, and worst case just change your router dns back.
Gets more complicated when you learn some devices are hard coded dns and you need special firewall rules to straight up block or forward those requests so they still hit your dns server but dont worry about this until you are comfortable with dns server you choose.
Really that bad?