On a short visit we would usually go to El Mercado in the morning, for breakfast first, then shopping. We think the Alamo is best visited late morning to late afternoon, the Riverwalk in the evening (although restaurants and bars get quite crowded then).
If you have transportation, consider visiting some of the other missions on the Mission Trail. Hop-on hop-off will also take you to a couple of them, particularly the park headquarters mission.
Check on what is going on while you are there. There is always something going on in SA.
Events Schedule. What's best about San Antonio are the people and the events, more so than the places to see.
There might be something that interests you, there might be something that draws huge crowds you might want to avoid at a place and time. On a winter visit when we were getting homesick for China, we particularly enjoyed the Asian Festival (February 4th this year). The Alamo schedules family events that draw large crowds (usually on Saturdays).
Between the restaurants on the Riverwalk and those in El Mercado, San Antonio can be a great foodie place.
In the RV, we've stayed at Traveler's World. Most of my many visits have been non-RV: hotel stays on business trips and family vacations, and staying with my daughter during the years she lived there.
