Maryville University has a parttime evening/weekend program, but it is fairly expensive. UMSL has quite the waiting list (2+ years), so I would look into some other programs as well.
I agree the St. Louis Community College system has a good program (same at Forest Park, Meramac, and Flo Valley). It's good that you are working on your generals right now, I always advise students to do that while they are applying and waiting to get into a nursing program. If you want to do your RN through the STL CC system, be sure to take chemistry. You have to have chem before you get into the nursing program with them.
Some other schools to check besides SLU, BJC, UMSL, STLCC, and Maryville are: St. Charles Community College, Jefferson College, and Lewis & Clark Community College in Godfrey, IL (about 30 minutes from STL).
You will not get in anywhere for the fall, most likely. Nursing schools can only take so many students per start, and most are waitlisted. But I would advise taking what you can now (A&P, etc), and get busy applying.
If you need info on any programs in the STL metro area, PM me, and I will get you the information.