Yes, track your hours with Hackatime or use the journaling system.
Yes BUT:
You can work on the same repo but in different forks
Your hours will be obviously counted separately
No, your project MUST be open source, otherwise hours will not be counted.
As long it's not part of other HC programs, yes you can! We HIGHLY suggest to create a new Github repository — it's not mandatory, but it will increase your chances of being approved, and will make the process much faster.
— In-Person Event
Anyone between the ages of 13 and 18 (included) can participate in Jackpot!
Yes! Participation is entirely free, just sign up and come to the venue!