Hi Cody,
For your Jr L1 bring your rocket, with recovery gear and motor retention.
Bring Masking tape, and anything else you might need to prep the rocket.
Bring your motor case and motor (if you have them already) - but do NOT assemble the motor.
Bring a camera, camcorder, Mom, dad, and friends etc.
Print out this form >>
https://www.nar.org/pdf/JRHPRForm.pdf fill in the top section, applicant information, (only)
Bring your NAR card. Bring money for launch fees (if any)
Bring your L1 Certified Adult Mentor - or meet him/her at the launch.
Be ready to show or explain the CP and CG of your rocket, and talk about your rocket construction.
Did you do anything different from the instructions? Be ready to explain why.
If you have a simulation or some calculation about how long the delay should be... print it out and bring it.
Find the instructions for assembling your motor online. Study them, then study them some more (don't even think about assembling the motor yourself) You just want to be familiar with the assembly.
Be ready to answer any questions the cert team, and RSO may have.
Last and most important - remember to relax and enjoy the moment... it will be over before you know it.
Have fun and good luck !!!