How does maternity leave work? I’m confused help.

I’m a first time mom and I’m working from home due to the virus. I’m so confused about how and when to apply for maternity leave. I’m die in July love in USA in Michigan. I’ve been with my current employer since February left my old job for better opportunity. Because we are all working from home I have no idea how to reach HR I do have a supervisor that I could probably ask him. If any of you ladies know how maternity leave work or if I even qualify for it please do help me out a little? Also if I can’t get maternity pay can I apply for anything else? Any and all help is appreciated. Thank you