well good luck. the amount of disinformation agents out there is tremendous.
www.ericdubay.com has some of the best information that is impossible to debate. he has his 200 proofs. (ack! website down... )
btw ericdubay is right here on steemit. here is a list of people he likes.
https://steemit.com/flat/@ericdubay/flat-earth-recommended-channels
the tags "flat" and "flatearth" both have some.. but the top posts are usually people against it, or claim to be.
Thanks.