Modify registration form fields

Hello everyone, I’m a beginner on OpenMRS and for the moment I’m still at the lowest level. I have installed bahmni, I am trying to record a test patient. I enter all the information and when I save, I get an error that prevents me from doing so. It seems that I can only enter a first and last name. For the past two days, I’ve been surfing the net in search of a solution, but to no avail. Could someone please help me modify these fields, or direct me to documentation on the subject? I’m currently at level 0 but I’m motivated to learn. Thank you