I might sound stupid for this but i would like to know how to disable the player use of speed, fly, noclip all that stuff

UnknownShadow200 🔧 Tue Sep 10 at 1:44:59 (2019)

For the list of rules that can go in a motd see the list in the "Host one for yourself" page. (Link is on servers page)

For example, to disable fly by default, change Motd in the server software's config/settings gui to "-fly".

If you wanted to only disable noclip on one map (in MCGalaxy), type /map motd -noclip

Thank you.