Nothing wrong with going with a group if that is what you want. I wouldn't advise doing it just because you haven't toured though. Touring isn't rocket science and it is quite possible to head off on an xc tour on your own especially if you have done some kind of self supported travel (backpacking, canoe camping, kayak camping, sailing, or whatever). Also if you are using that AC maps that helps a lot as well. If you have no camping or self supported travel experience then definitely do a few shakedown tours, but my two companions and I didn't find it that hard to just take off on the Trans America with no previous touring experience. We found that our other outdoor experience carried over nicely.

Since you have plenty of time before then a few short tours should be possible even if they are just overnighters though so why not take advantage of that?