Content is just about anything. Keep it short and interesting. Web readers don't spend a lot of time reading. Rotate often. A short incomplete list follows.
- Info about FIRST
- Info about Game
- link to newspaper articles about you
- team history
- pictures
- what you are going now
- Spotlight a student or mentor
- Spotlight a sponsor
- talk about what your graduated FIRST students have done
- Talk about other teams
- Robots in the news
Lots of stuff qualifies as content.
You are building content to showcase your team and FIRST.