Oh my friend, are you ever in luck with Indian food. Go to the intersection of Hillcroft and US 59 and pick one. Endless strip malls filled with authentic, hole-in-the-wall restaurants. In particular, Shri Balaji Bhavan has fantastic vegetarian South Indian food. People line up on the weekend for the dosa. More high end is Pondicherry, off Kirby north of 59. Haven't eaten there yet, but it's supposed to be very good. Also on Kirby is Madras Pavillion, which attracts not only Indian and Texas Caucasian diners, but Orthodox Jews as well (?).
For "asian" food - hit Bellaire west of Beltway 8. Again, miles of strip malls packed with Chinese, Thai, Korean, Malaysian, etc.... I like Tofu Village (Korean), and Banana Leaf (Malaysian and more) is supposed to be very good.
In midtown Houston proper there are remnants of "Vietnamese town" - Mai's is famous (and was on Anthony Bourdain's show) and open 24 hours. Kim Tai (despite the name) is a tiny little diner with very good Vietmamese eggrolls and Pho.
Up on Long Point (runs north of and parallel to I-10) there is a BYO place called Veng Tai - excellent Thai food. Next to it is a fantastic Mexican place, El Hidalguense, that has BBQ goat on the weekend. Both of these places look scary as heck, do not be dissuaded.
Speaking of Mexican... Do you want TexMex or full on "real" Mex? Take your pick. For tex mex, I love Teotihuacan on Airline in the Heights. Haven't tried, but La Fisheria off Shepherd south of I-10 is supposed to be awesome Mexican. One of the best Mexican restaurants in the entire country is Hugo's on Westheimer. More "fine dining" but it is worth every penny. Supposedly their Sunday brunch is spectacular. And don't overlook the taco trucks. There are gems out there (the one that parks on Alabama across from the West Alabama Ice House is a city favorite).
So I could go on, but I won't..... you'll find your favorites soon enough. Houston's not so bad. Once you get through the summer, it's pretty nice here.