when i am trying to make a face from wireframe i get the following error:

'The wireframe model contains edges which can not be connected'.

can any body help where is the problem. Thank you.

it just means the edges aren't connected properly.

also you can only make basic shapes which can then be filleted or added, etc to make more complex ones. It just takes time to get the hang of.

You really should do all the Gambit tutorials which will teach you all these things in hours. I can't stress this enough.