Focus on making your server unique, and think about what could make it more fun. Listen to your staff and users suggestions and preferably get to learn some programming if you don't, it would make everything a lot more easier.
Try not to spend all your money on gmodstore. I would try to find a decent map and in the future make some edits or even make a new map. Try to balance User and VIP jobs and having a lot of VIP jobs will make people not want to play.
The best servers are the ones where the owner and mods aren't stuck up. Most people join to have some fun, it makes the experience better if the people running the show are looking for fun as well.