If someone explains the rules to me I'd be glad to join in (providing I'm not somehow in school.) The only day I have plans is on the 15th, I'm going to be at a basketball game playing for the pep band.
Just as a heads up: from past experience we know that people with under 100 hours of TF2 or with over 100 ping generally have a difficult time with highlander, and afaik you fit both categories. I think that because you've got experience playing an FPS as a team (CS:GO) it won't be so bad, but if you lag all night/have no idea what you're doing that will suck for both you and your team. I'll let this be your decision
The brief rundown of highlander: 2 teams, 9 players per team, exactly 1 of each class per team. We usually play three maps, the win conditions/rules change depending on the gamemode. There are some unlock restrictions but it's only the really bullshit stuff that gets banned. It's taken fairly seriously, i.e you're expected to play as a team and know (or agree with your team) roughly what your class should be doing for each map/situation and then be able to do it fairly competently - I can help with this if you don't know, so can the highlander team/highlander regulars I think. It's great fun and I love it
Those are the most basic of basics, if you (or anyone else for that matter) want more give me a poke. Just beware that I might start talking about the complexities of holding the last point on pl_upward for the next 5 hours