Hey there - first, thank you to @cat for the mention.

I have a product to help with chat moderation on discord, telegram, x, and reddit: #watchdog

Now to answer your questions:
1. Yes
2. I promoted it on active subreddits and in the video game it was related to (I used to run a fairly successful Rust game server)
3. Be active, respond to new members immediately and make them feel welcome. Make sure you’re doing whatever your community is related to all the time - mine was related to the video game Rust, so I made sure my discord status was always online in Rust. I did some other things like offering giveaways to people who invited the most members etc.