Can I link an account from my Android smartphone with my data and Disroot (Nextcloud) account?
Of course. Check our howtos:
Same goes for email
When I first install Android (new smartphone) he asks about email, backup accounts, etc. In the first setup. @muppeth Are we talking about the same thing?
I don’t know what specifically you have in mind as it depends on the version of the Android you are using. My guess is that those refer to your google account, unless you run google free version of android (which you should), in which case it does not ask you those things as they are google related.