I did it, I did it, I <insert whatever expletives you like> DID IT!!!! Sorry, but after banging my head against that diamond-titanium-concrete-reinforced steel wall till my skull broke and smeared it with gray matter I had to shout it out to someone. 8D Woohoooooo!!!
Wow, that was a "training" mission? Picked it up a couple days ago for Xbox One and all I've done so far is the training missions and all of them up to that one were pretty simple. A couple took 2 or 3 tries, and I could see what I did wrong almost immediately, but getting in orbit of the Mun took me forEVER; a few dozen tries at least. About a dozen tries ago I'd decided the mission was broken and just plain impossible, but I couldn't quit even when I really wanted to.
I'm not complaining, I'm liking the game so far and can see its potential already, even just from the training missions, but I don't think I've ever done anything harder in a game than getting that stable Munar orbit established and I've been playing computer games pretty much all my life...at least 30 years of it anyway. Yeah, I think I'm totally hooked on KSP. <3 My love to the creators.
P.S. - to anyone looking for hints on the mission, the best advice I could offer is just keep trying (and make sure you do the previous training missions a few times till you're comfortable with all the things they teach you.) It IS possible and completing it successfully will teach you piles of things about the game (likely more than I'd remember to relate.) Best of luck to ya.