Stock Android does not have tools to do that verification. Just verify it from the desktop and then send it to your Android device.

But I don't see how verifying the apk signature would help if your concern is that "you have bare to none knowledge how it works". The only thing that would fix that would be if you actually learn how it works.

Luckily, unlike other stores that are closed source and actively and purposefully hide from you what they do, F-Droid is open source, so anyone can go to the repo holding their source code and learn how it works, or build their own themselves, as long as they wanna spend that much effort.