How to make a creative minecraft server that you can't break blocks on?

The point is to avoid block breakageor ban them from breaking blocks. This because kids will be playing on the server with their parents and we minecrafters all know about the void. However the kids enjoy digging straight down… A lot lol. They also want access to all the items hence why I asked about a creative world.

I'm not sure what you meant by breakageor but if you want people not to destroy in a creative server than install a plugin called world guard if you want a specific place protected.

World guard the entire map.