Hygiene is the most important thing. You will hear many routines on here to stay safe. They know what they are talking about. Make sure to wash your hands thoroughly. For now, one use per catheter. Don't open the package until you are ready to use it. Sanitize everything. Catheter is clean so don't sanitize that. Even after that, you could still get an infection. If you do then drink cranberry juice and see a doctor if possible. It will feel weird and maybe even hurt a little. If you feel stabbing/cutting pain, you are doing it wrong.
Now that you are properly aware of the risk, it is fun. Get a diaper ready before hand because you are going to leak with no control. Put on a good diaper and be aware you will flood if you sit down for a while and then standing up. First time, I wouldn't keep it in over a day at most.
If any veteran can chime in on anything I forgot please do.