You’ll want to use a VPN like Mullvad, Proton or IVPN (some, including Henry, recommend Windscribe, but I personally don’t) if you want to start out with that.
MySudo, I heard, was great in not giving out your real phone number. I have Google Voice, but for a different reason. Limiting advertising is as simple as using a Firefox-based browser, hardening it to the nines, and adding uBlock Origin, Multi-Account Containers and LibRedirect (that’s my method of doing it).
For aliasing, it’s a good idea to do if you don’t want your real email exposed. I use SimpleLogin for aliasing on different services, and I have particular aliases for particular purposes (since I’m a relatively unknown public figure, I use my pseudonym everywhere).