You want 3 features, and then you can decide which product(s) satisfy them:
-
A router
-
A wireless access point (often included with the router for consumer stuff)
-
A DNS server that can block ads.
A good cheap set of options that would set you up to play and grow would be:
-
UBNT ERX for $60: https://store.ui.com/us/en/products/er-x
-
A UBNT Wifi 6 lite AP $100 https://store.ui.com/us/en/products/u6-lite
-
A pihole (if you have a Microcenter nearby you can grab a Pi 3 for like $25, if you want a case it's probably $10 more).
You can run the pi-hole software on a lot of other things too https://docs.pi-hole.net/main/prerequisites/.