Q: Setting up network directly behind my ISP provided router

Hi there, On my router/modem I cannot change the DNS entries, thus just using Adguard/PiHole for DNS blocking ads doesn't work. Would a seperate Router circumvent this problem? Could I set up Adguard (or PiHole) on a Raspberry and use it as a DNS server for my home network?

The plan would be to use my ISP-provided router just as a modem to connect to the internet. Then us a second router to provide my home network, where also Adguard/PiHole can do their thing.

Would this setup work and how would I need to configure it?