What’s a nice guide?

Follow this to get it installed and follow the configuration steps to set it up as you need it (I wouldn’t bother forwarding to another server but setup root hints instead and add a timer to keep them upto date):

wiki.archlinux.org/title/Unbound#

Then add these configurations to get doh or dot working:

wiki.archlinux.org/title/DNS_over_HTTPS_servers#U…

If you want a spoon-fed guide, then a search engine may help, but really, it’s quite easy.