I run a number of social sites (like Facebook but way smaller) the number one thing is just be involved. That's it really, be available 24/7, remember there's a person behind the words you see. That's pretty much it.

Edit: also stay off Discord, it's not your platform, you could be removed from there at any time. Build your own platform, and always implement whatever your members suggest. Since you're planning on having developers there, you could just open source it all.