The first thing you should do as soon as the accident happens is to seek medical assistance. This brings a double benefit. On the one hand, you will take care of any ailments or physical injuries you may have suffered as a result of the accident. On the other hand, you can start keeping a record of all your medical expenses. Save all invoices, receipts, and anything that serves to prove that your injuries were real.
If you believe you are uninjured after the accident, call for assistance anyway. It may happen that you have injuries that manifest over time, and they deserve attention. Not only for your claim, but mainly for your life: an internal spill or other serious injuries sometimes manifest themselves a few days after the accident. Not treating them in time can be dangerous for you.