In the sidebar for that server on discord there should be a button that says "Create Instant Invite". Just make sure you have the correct server selected or you'll create an invite to the wrong one. Also, it will probably be a good idea to toggle the link to never expire, otherwise you'll need to create a new one each day. Once you do that just copy and paste the link that it gives you to this page. Unfortunately it doesn't seem to be possible to access it without that link (I tried looking up the name but couldn't find any way to locate it using that). If you still need help with it let me know and I can try to get some screenshots when I get home.

That sounds like a great idea. Let me know if you (or anyone else) set one up, I'd join.