Hi Mitchell,
Welcome to Ice In Space
The 150 would be the aperture in mm
(so that equates to a 6" scope)
The 750 is the focal length.
Any EQ mount can be tricky and sometimes unstable, because they get into all sorts of weird positions. This is usually overcome by correctly balancing the scope with counter weights.
A more stable mount is the Dobsonian mount.
Much easier for a beginner to use.
And generally cheaper to buy.
Edit:
Ah! Murphy you just beat me.
BTW: The scope appears to be a parabolic Newtonian Reflector, not a refractor.