So I found out my cat is pregnant. So, I don't know how to deliver the babies. Can you tell what to do?

I also need to know how do I know she will have them it is a stray so I really don't know how long she has been preagnant. I know she will start bleeding but is there any way I can find out B4 so I can get some help(my neighbor)

You don't have to deliver the babies. Motherly instincts will kick in and she will do all of the work herself. Make sure she has a clean, warm, comfortable place to do it and easy access to food, water, and litter when she has finished. For the first few days after, check to make sure that she is eating, drinking, and using the litter box as she should be.