Most first-time driver’s license applicants must take and pass a Knowledge Exam consisting of a Road Signs and Road Rules test.  All information you need to pass this test can be found in the Driver’s Manual

There are many sites that have practice tests. Each of them has questions that are similar to the questions you will find on the actual test.  Visit more than one of them to get lots of practice.
DPS site internetforms/Forms/DL-7.pdf 84 questions in Appendix C of Drivers Manual quiz-1 8 tests with about 25 questions each
Driver License Test Texas App > 150 questions Texas-Teen-Driver-Education/dmv-practice-test 84-texas-dps-permit-review-questions-flash-cards About 84 questions