Still one week to participate to the PicoCTF: https://picoctf.com/
It's accessible to everyone and if you're a highschooler or a college student there is prizes:
- 1st place: $5,000 + paid trip to Carnegie Mellon University for the top team!
- 2nd place: $2,500
- 3rd place: $1,500
- 4th place: $500
- 5th place: $500
- 6th-10th place: $250