I have been through the wiki etc...

But how do i access the files on the server?

and how do i get admin rights ingame?

You don't have access to server files.

Every setting in de lfs cfg file can be set/changed at the host server configuration screen. Admin password is being set upon server creation. Just try; https://www.lfs.net/hosting

On-demand Hosting (hourly) only starts ticking credit away when the server actually is started.