Should I open a claim and how long do I have to repair my car?

I was in a minor car accident in which I backed in to a column in a parking lot. There is some rear bumper damage. I have a $500 deductible for collision, but I don't have the $500 right now if I open a claim for repairs. My questions are should I open a claim? If I don't have the $500 deductible and if I do open the claim, how long do I have to repair the car?