550,

Get an adjustable mount (2 piece) at the hobby shop, and ask questions 'til you are starting to bug them, then come back here and ask more!
Sounds like you have a 46-60 sized mount in there now-no good.
As several have suggested, don't try to fly this one first, unless you have a GOOD instructor. (I've seen "instructors" that could hardly fly trainers!)
Get a trainer, and use the engine/radio in that until you get a season (or what's left of it) under your belt.
Have fun, persevere, and ask a lot of questions here!

Jetts