gabievictoria I'm pretty sure you can't make a new hospital/school and staff it in the way you're describing. The game already has 1 default school and 1 default hospital, staff and attendees are programmed to use those lots. You follow Sims to these lots as part of the game mechanics, so they are fixed.
You can edit the existing ones using bb.enablefreebuild but you can't create one that would be automatically staffed like you want it to be. I've edited them all successfully because I wasn't keen on them in their original state. As I said, you could design some and place them anywhere but getting them full of Sims assigned to the correct roles would be your problem. I've redeveloped Newcrest myself with malls, parks, roller rinks and things like that.
Custom Venues are arriving as part of Adventure Awaits but again I don't know if they would help you build a functional school until the pack arrives. I'm seeing kids camps and things of that nature. Business and Hobbies lets you create a business where your Sim can mentor Sims in certain skills.
If you are on PC and use mods I don't know if there are any that might help you achieve what you are wanting to do.