Plane-o
Falcon has given you a great summary. The only thing
I would add is to encourage you to resist skipping Basic.
Many (most??) who start IMAC will begin in Sportsman.
I found that even though the Basic manuvers may be
something an active flier has been doing reasonably
well for years, there is more to IMAC competition than
just doing simple manuver elements. The issues of
being judged and having to do those manuvers consistently
well and on call, changes everything - it makes it much
harder than the punching holes in the air that we all tend
to do at our local fields.
Good luck
Bruce