can i get a misdemeanor theft charge expunged or sealed

In general, if you have been released and the charge, if any, has not resulted in a final conviction and is no longer pending and there was no court-ordered community supervision under 42.12 of the Texas Code of Criminal Procedure, unless the offense is a Class C misdemeanor. You would need to consult with an attorney to file the proper motion and determine if you are entitled to expunction.