Hello, I have a question how to create a server in the create, I can get detailed instructions

Set it up like you would any other forge server, and put Create in the server's mod folder. Make sure anyone who wants to connect is using the same version of forge and Create.

Me and my friends are making a server rn, will come back with updates if we get it to work. Right now we get "minecraft incomplete set of tags received from server" error when connecting.

Me and my friends are making a server rn, will come back with updates if we get it to work. Right now we get "minecraft incomplete set of tags received from server" error when connecting.

you and your friends gotta make sure you have same mods as server

Did that, didn't work. I found a public Create server (Create Technical) and used the mods versions that they used.
-here they are: https://www.curseforge.com/minecraft/modpacks/create-technical

Which jar are you launching to start the server? Make sure you're launching the one that starts with forge.

Sorry, this is the issue tracker, not a help desk. There should be a link to get help on the project page