Flat earth society may just be controlled opposition (look it up) so they have lots of inaccurate information. Alot of stuff that NASA used to teach has been changed too and some of their current stuff is probably wrong. Doesn't mean it's flat or its not.
My suggestion to you is to prove it to yourself, one way or another. Do experiments that prove it. Keep in mind that an earth that was much larger than we're told would have some similar results in some experiments and observations to a flat earth. Lots of nice YouTube vids on the topic, lots of garbage too. This is one of those things that noone can prove to you, you have to see it for yourself.
Question is, does it matter? If so, why?
What if NASA lies about everything, the earth is flat, the sun is close, and the moon too.. Now what?
Ill leave you with a final question that's not about the shape, but about the motion:
Why is there absolutely no way to measure any of the various motions of the earth from the surface, no device whatsoever that we've been able to invent can see the earths motions however a simple gyro can see a airplane or ship in all its various motions, on the surface and above.Einstein recognized this fact, maybe it means something. (and no, the focoult pendulum doesn't show it either)
I'm not a flat earther or large earth proponent. Nor a ball earther.