Steps to build controls on a Dashboard

Looking for help getting started with building out a complex dashboard to simplify life.

I have a few media devices, all defined and working in HA.

When I build a dashboard, I get the very nice last, play, next, with album art and progress bar.

First, make friendly buttons for playlist and a bigger album art

the entity can get the album art as the card shows it, but how would I access it for something like the ‘Picture Entity card’?

The owntone server I can select outputs, they are entities in HA, how would I make the toggles?

Thank You in advance, point me in the right direction would be great