Smoothing after bisecting

Hi,
I have bisected a sphere on an angle and the surface is very uneven but when I view in Edit there don’t appear to be any vertices.

What are my options for smoothing this surface or should I have approached this entirely differently?

Thanks!
Bryony

Clean up the mesh first by merging redundant vertices. Add an inset on the top and bottom Ngons to create control loops.

I’ll try this. Thank you!