I think you got the makings of a great PSA here but it's just not there yet. Your shots are great but it needs more narration I think. The sound of your VO is also tinny too. Rerecord this but add more to it. Maybe explain that crossing the sidewalk with your bike is important to your safety. Then narrate as Keith is doing it the wrong way. Then say something like, "Let's try this again, but this time, stepping off your bike before crossing," or something like that. Your end title is also not using correct English. That needs to be fixed too. But the idea was great, it was shot really well, and like I said, it's almost there! Make those changes and it'll get there!
Write something about yourself. No need to be fancy, just an overview.