My SO knows the New Braunfels/Seguin area well, so here's SO's take:
It's right off of I-35, and near the Guadelupe River, so if you are interested in rafting, tubing, kayaking, or canoeing, you're in luck. Go to Whitewater Sports for camping and water sporting rentals.
For cultural events, there's not much in the immediate area, with one exception:
Gruene.
If you're a dancer, check out
Gruene Hall. If you like wine, go to
The Grapevine. Gruene (pronounced Green) is quite near to Seguin, and it's a quaint little town with lots of shops (antiques, an amazing old general store, pottery and craft shops, etc.).
Folks in that area of Texas are used to driving a lot, so San Antonio or Austin will be likely weekend destinations for you. San Antonio is vibrant, with lots to do and see, and Austin is a fantastic city, with all kinds of amenities and cultural events. San Antonio is closer to Texas Lutheran (about 35 miles), but Austin is not too much further (50 miles in the other direction). If you are a blues or jazz fan, Sixth Street in Austin is definitely the place to go. Also, if you're into bats, go to Town Lake in Austin in the spring and summer and watch them fly!