I found this pic on the internet. Notice the "Backface Culling" section.
Make sure that's set to off.
The picture is of the attributes of the selected object, so make sure to select the sphere, go into the attribute editor, and turn that to off (also check under Window->General->Settings/Preferences and see if you find an option for backface culling. I'm pretty sure there's one in there, just can't remember which tab)

Also, select the vertices from the side view, that way you know you're selecting the ones on both sides. then you can move them around in perspective view.

Also check this site out. It's got quite a bit of inormation and explains a few of the options and things of that nature. It also explains the tools and where they're located.
https://caad.arch.ethz.ch/info/maya/m...Basics.fm.html