Thank you both.
I tested the Neo Store. It is a quite confusing. If I understand this all correct I don't gain much over the 'old' f-droid client. I can live without seamless updates. ;-)
I only use a handfull apps. My goal was to set up the phone with the oportunitie to ditch google completely if I want.
Threma Libre, Signal apk the rest from F-droid.
I ended up with Signal, GCam and one paid Weather App from PlayStore and the rest out of f-droid (DAVx5, Organic Maps & Weather).
I think I stay with that setup for now. I'm unwilling to configure DAVx5 from Play.