You've seen pictures of the earth from orbit, right?

You probably mean that you haven't engaged in all of the crazy theories and arguments put forth by flat-earthers. But that's doesn't make your very simple observation-based opinion any less justified. Direct observation can and should eliminate the need for lots of hemming and hawing.

> Of course i believe in global warming, though ive never read a single paper / study on it.

There are many accessible descriptions of global warming and the evidence for it written for different levels (uneducated/child; HS-level; university-level).

> Of course i believe in evolution, i went to a school where they told me to believe it.

That sounds like a bad experience, and maybe that explains some flat earthing. When I was in school we were presented with a lot of concrete evidence for the evolution of the species, and Darwin's original was even required reading.