Lived in Memphis my whole life, 60 years. First The Rendezvous wouldn't even make the top 10 of Memphis BBQ. Interstate, Central BBQ, The Commissary, Cozy Corners, The BBQ Shop and even Corky's all have better BBQ IMHO. Don't limit yourself to BBQ, there are several great restaurants throughout Memphis.
You have to go check out The Pyramid, it's now owned by Bass Pro and they have poured a ton of money into it. It's now a shop/hotel/museum, and big time tourist attraction. Since it's new it's very crowded on weekends.
The river walk is worth some time, from there go check out Mud Island, The Peabody Hotel and perhaps catch a ballgame at the Triple A Memphis Redbirds ballpark.
The zoo is one of the best in the nation, check out the pandas.
If you like to gamble there's always Southland Park just across the river or some bigger casinos 30 miles south at Tunica.
Several small gun shops in Memphis, perhaps Classic Arms in Cordova is the best with Guns and Ammo second.
About 80 miles east of Memphis sits Shiloh, a must for any Civil War enthusiast. Several smaller battlefields throughout Western Tennessee and Northern Mississippi.
Last remember one thing, know where you are going, there are several parts of Memphis you don't want to wind up lost in.