A backflip may seem simple to learn but there are many components involved to prepare yourself instead of injuring yourself when you land. If you are interested in learning how to do a backflip, check out the video below as it would guide you with the necessary steps to help you nail your first backflip.
Since performing a backflip involves gravity (unless you're in space), there's still a chance where you would hurt yourself when practicing. There aren't machines or apparatuses that would help you with your form but you can practice on trampolines and land on softer surfaces before you move onto pavement.
Always be patient when practicing and take it one step at a time. Safety first! Good luck and have fun.