It seems kupala84, that you're on the very 'start of the 'journey' in every aspect - playing and designing wise- in the adventure calling OFP. That's ok, but when I start to drowning into this game, I was only a player first; I played my brains out for almost two and a half years, before I even start to think of touching Mission Editor. Not like I recommend you something similar, and on such scale, but it would be the right path to go on.
About your question; download this mission by all means, it is one of the best, if not the best user mission out there, but do not play it yet; regarding your 'playing' expirience' you will not enjoy it right now. Just save it on your hard disk, and then go back to her, when you're 'ready'.