I am a don't-know-er on the shape of the earth.

All i can say is that there is a lot bad information out there.
The theories have holes in them.
The evidence from NASA is contaminated with known falsehoods.

but the second part is quite factual.
You can see it in things like Venus' transit across the sun.
(its a zig-zag, not a straight line)

But, but, if you believe in the hollow earth, where the people living inside have a sun of some sort... are they living in a Dyson's Sphere?