I've used Turbocad through several versions now. When I first got it, version 9 I think, I just got terminally frustrated trying to use it. I couldn't find all the ropes and handles I wanted to make it do things. That may have been my myopia, because I'd worked on mainframe CAD programs years ago and this didn't have the same command structure.
Finally I got out their 2D and 3D tutorials and went through them. Seeing the way they built things was the leg up I needed. Once I could kind of see where things were going I could poke around for the additional construction tools.
Also, I initially treated it like a drawing board, stretching extension lines over to another view just like I would with a drafting machine. After I was reasonably comfortable with that though, I started actually making 3D solids so I could generate any kind of view, projection, section or whatever to get to the dimensioned drawing for the shop.
Still often I'll often just throw a few lines and circles down to get a feel for proportions, clearances and things if I'm making something ad hoc without a complete design and dimensioned drawings.
Interestingly, a few years ago I was in a shop for a couple weeks that built custom machines for manufacturing. Some of it was pretty complex indexing table assembly machines and so forth. The owner was a degreed engineer and did all the design, but he never did generate a complete machine drawing set. He'd have an idea to start with, lay out a few weldments, look at places for slides and ballscrews, then print out essentially just a one page sketch of stuff with essential dimensions and take it around to the machinists. By the time they'd have that done, welded, and heat treated (stress relieved) he'd have more sketches of what to machine next. Damndest system you ever saw, but lovely, lovely machines.
"I am often asked how radio works. Well, you see, wire telegraphy is like a very long cat. You yank his tail in New York and he meows in Los Angeles. Do you understand this? Now, radio is exactly the same, except that there is no cat." : Albert Einstein