Registry Help

Hey ladies! I am pregnant with my first baby and i just wanted to ask a few questions about baby registry.

What are the essentials that need to on there?

When do you share your registry with friends and family members?

Whats a good website to set up your registry on?

I honestly have no idea what im doing, the only person who has my registry right now is my mom, i also made her my co-registrant and i cant stop her from buying things, but i have no idea what i need. I dont have too many friends that i have babies, and i also dont want to tell too many people because i dont want them to know im pregnant so i dont have too much help when it comes to this. Any advice? At this point i could use all the help i need.