Random apps are going to be harder. Best option for your home network will be to setup a pihole. I’ve causally followed it but never actually set one up myself. I’ve heard it’s great.
It is possible to set up pihole on the free tier of Google cloud and stay connected to it at all times through a VPN. I have been using that for a few years now with minimal issues. Here’s a tutorial on how to do it.
You’re not going to have much luck blocking ads within apps with any other option I’m aware of. Maybe android has some OS wide ad blocking but iOS doesn’t.
Android has dns66, which kinda works; per example, on youtube, home ads are not blocked. Video ads are though, besides youtube's own ads, which are baked into the app
I tell all my friends to use Brave browser. It works fine out of the box. I've also heard some success with Firefox Focus. You can watch youtube in there too without ads. Configure the settings to allow background audio and you can listen with your phone screen off too.
The Brave browser was full of ads for crypto currencies last time I looked into it. It hardly seems like a good option for someone who is trying to avoid ads.