Do u have to be 21 to get into all the clubs in Texas or can you be 18?

-Im moving to tx soon for school and 'm from Germany and you can do anything here at 18, so I'm wondering how they restrict the drinking and stuff like that.Not all clubs, but being under 21 you may have a covercharge at some clubs/bars.
Some trashy places are 18 and up. But if you're under 21, be happy getting into any place!