well, I'm not sure a trial in the beginners world does work. I did have fun in Athens, but it was ridiculously easy.
My first real company was in Glasgow, GW3. I did make quite a few blunders, but survived by identifying them quick enough. Going IL-62M in 1998 did cost me around 20M$, when I was 3M$ in weekly profit, and terminating the leases and laying off the pilots nearly killed me. But I did it quickly enough. Accepting losses immediatly to avoid more loss later saved my back, then.
I made several other blunders, like flying with tech stops, opening level 3 bases in airports where the potential for 737 was 3-4 planes(Corfu, iirc), but somehow managed to survive, and finally thrived when I began to replace my leased CRJ100s by bought A148. This move took me 10 years, but made me change of dimension. Ended the game with 600+ A148, around 200 737, quite a few 777, 12% margin, and a few stupid-but-fun transatlantic 737 routes.