If this question had been asked yesterday (April 11:smile I would probably have received it with a smile. .
Today, my arms fall!
never heard of solids of revolution? and the sphere is perhaps for antonomasia.
so with a beautiful extrusion/base in revolution 180° of an arc (semicerchio) solve immediately.
and then the loft as you would? What are the two sketches to join?
I still recommend you to do the easy and always useful tutorials of the program.