No worries
Hope you enjoy your trip. Here's a few more tips:
If you go to San Marcos, don't miss visiting the huge outlet mall for some cheap shopping! You can't miss it - it's right on I-35, about a mile long...
If you're short on time and head North, hang a left somewhere by Georgetown and go west to Burnet. There's another CAF outpost there although I don't think it is as big as San Marcos.
Finally, any flying you do, if possible go and fly over Lake Travis (the big lake to the west/noth of Austin) - it's beautiful from the air.
Have fun!