I'm basically in the same place you are. I just started a server as of December 30th, and quite honestly, it's difficult. I personally went with GriefPrevent friendly survival. However, I have also left myself tons of room for expansion. - With the right host, you can do every single gamemode. I'm even going to expand into skyblock, and so much more.
Do what you think is right in the beginning, give them something to do. Then, from there, continue to expand outwards. Also, one thing that is *critical* is taking feedback from players. They're the community. They don't need to be a part of your server