Welcome! I'm from near Nashville myself. There are some pretty good deals on Craigslist in Nashville, although you need to make sure it really is a good deal (sometimes items are ridiculously priced), and you'll want to clean any items really well before setting them up.
Have you discovered Aquatic Critter on Nolensville Road in Nashville? I think they're the best local source for fish and plants, even if they are a little pricey. Most of the advice they give you is good, too, although I usually come back and double-check it with the information on this forum. They also have a website that tells you which fish and plants they get in every week ("new arrivals"). Aquatic Critter
You'll enjoy this forum--lots of nice people and helpful information here. I spent a couple of months thinking/planning/scheming
) about my tank before I set it up, and that's where this forum was really helpful. I think planning is 75% of the fun!