What should I do after I fall to protect my rights?

You should take stock of where you are and what’s around you. You should take immediate note of what it is that made you fall, and try to get photographs of it. I would also try to get the identification, name and address and phone number, of anybody who witnessed you fall. You should see if there’s video anywhere, and you should find out who owns the property of where you fell. Don’t do your own investigation. Hire a lawyer right away. Contact a good, competent lawyer who has a lot of experience in fall cases, and hire him quickly.