natural birth control methods

I am looking for ways to naturally avoid pregnancy. I'm going to stop taking birth control in a couple days because it is effecting my body badly. Please give me tips and info on natural birth control methods such as NFP! I'm new to all of this so I'm nervous but I just want to take care of my body so I'm done with birth control pills. Also, please let me know about any apps you use to do this! Thank you