I believe you are saying that your boyfriend borrowed your vehicle and where he parked the car it was damaged by a vehicle that rammed into other parked cars. You are lucky to know who caused this and is at-fault. If you have not already contacted the police to report the incident I would do that first. Even if it has been a few days most law enforcement agents will come out and write up a report.

You also should speak with the at-fault person and get their information - especially name, phone number, address and insurance information. Then contact their insurance company to submit a claim. If the person did not have insurance you can either go after them personally or if you have collison coverage you can submit a claim through your car insurance.

Seven Steps to Filing Your Insurance Claim is an article you will find helpful.