Everyone is welcome to participate in the Epics games! Unless you have a lot of free time on your hands between now and Monday night, however, you probably won't be able to complete the Epic 39 by its closing date. However, you are still welcome to play, you just can't be included in the official results if you finish after the deadline.
We keep the start files online for past Epics, and players are welcome to play through some of our previous games, then compare their games to the results that the other players posted. In some cases, the scenario files are also included, so you could play the same Epic with the same rules, but on a different difficulty or with other changes. You are also welcome to post about your experience with those games here on the forum!
If you are interested in playing an official Epic, we will be opening a new Epic as soon as we're in a stable patch situation. As far as I know, 1.20 is still due out "real soon", although it's possible that it was put on hold again (maybe due to the Age of Science bug?). In the mean time, you probably want to review the information on this page
, and the ones it links to, so that you'll know the ropes.
There are "RB" succession games going on all the time, and there's usually a spot or two for new players when new games begin. You can keep an eye on the SG forum over at Civfanatics, or watch this thread
for information about new games that are starting up. With succession games, since your choices affect other players, it's probably a good idea to read through several games before you begin, to get an idea of the norms and expectations for succession games.
I hope this answers all of your questions, and I look forward to seeing you in a game at some point!