where to stay?

You could stay on the river walk or somewhere down town.  If you want something more quiet, try the outskirts of San Antonio, hill country. 

If your budget can handle it, stay at one of the hotels near the Riverwalk North. Lots of things to see and do that are within walking distance (it is downtown, so you wouldn't want to drive as much). The Alamo is right there. Be sure and go to the Menger Hotel  (it is the the right of the Alamo as you're facing the Alamo). Go to the restaurant and ask for the Mango I've Cream. It is made on site.