I am far from an expert in modeling in MS. A couple of things that may help.....
Switch your select mode to "vertex" to select points on a line.then you can move individual points. In that mode you can also select two points to divide a face in the pulldown
menu" face" to create additional points. Under "tools" check out "extended primitives" they are sometimes a helpful starting point for arcs ,etc.. Also try out "lathe" on some of
the basic shapes to create arcs you can manipulate.