Congrats on getting back in the saddle!

I know from my own personal experience, it was about 2 weeks of riding before the soreness in my body went away. I just steadily rode a little longer every time I would get on the bike and by the end I was feeling pretty good. If you are still having issues after that I would definately take you and the bike back to the LBS for them to take a look at your fit.

Most importantly, HAVE FUN!