What does it mean when I have a Texas Provisional Driver License...?

Question

and it has LOFS age 21 or over on the back? Also it expires on my 18th birthday (17 now).

Answer 1

All original licenses, other than an instruction permit, issued to persons under 18 years of age will be marked "Provisional."

The license will be vertical and will be dated to expire on the applicant's 18th birthday or next birthday occurring after the date of issuance.

The LOFS means that someone 21 years of age or older must be with you while you are driving.