@Nhu_Gay_Me are you a member of Toolforge yet? That seems like the first thing to start with if not. https://wikitech.wikimedia.org/wiki/Help:Toolforge/Quickstart is a good place to start reading about the steps needed to get a Developer account and use it to request Toolforge membership.

When you are a Toolforge member you can use https://toolsadmin.wikimedia.org/tools/create to create a new tool to host your wiki.

Once you have created the tool account you will be able to create a new GitLab repo from the tool's info screen in toolsadmin (for example https://toolsadmin.wikimedia.org/tools/id/mwdemo).

When you get this far (Toolforge membership, new tool to host the wiki, gitlab repo associated with that tool), ping me and I can work on getting your new git repo bootstrapped as a fork of https://gitlab.wikimedia.org/toolforge-repos/mwdemo. That will also give me a chance to practice the steps needed so I can update docs for other users in the future.