Need help learning to ride the metro bus in Houston

Please don’t make fun of me. My car broke down right before I moved here, and Houston is not exactly super walkable. I have the metro app and I know how to plan trips and purchase tickets, but I am to anxious to actually get on the bus. I have seen others say that there is a button you need to press right before you stop and other say not to press it. I get very anxious when trying something new. So if anyone who rides the bus could give me a little walkthrough it would be much appreciated:)