I lived in that area for 5 years and am quite familiar with it. That is a tough Terminal as Uber/Lyft/Taxis cannot really go all the way to where the ship is as it is Restricted Access for Military/Navy Personnel. There is a special Uber driver waiting area and drivers are readily available. BUT it is a 1/2 mile walk from the ship to get there. Could potentially see if there RC can provide or rent out wheelchairs if the elderly passengers can't make it that far.
Additionally, There may be a few NASA souvenirs at The Cove. But the Exploration Tower is really nothing special and if you are trying to explore the area on your own...that should really be skipped. I'd recommend going to Cocoa Beach instead. Specifically the Ron Jon Surf Shop area. There is a little surfing museum, lots of good souvenir shopping (Including NASA souvenirs), The beach, places for food and drinks, etc. The Cocoa Beach Pier is also nice, but less options for shopping. That is better if you want to get some food or have a Drink at the Tiki Bar at the end of the Pier. There is really not much in the Port Canaveral area so if you have the time, I would definitely recommend skipping the Port area and going to Cocoa Beach instead!