For your first FAC you are only going to get rimfire. Go for .22lr, ask for HMR. TBH, if you ask your FEO for a .223 as a first gun, he might decide that you know so little about firearms that you should not have a ticket at all. Frankly, I agree. Go for FAC air to start with.
Ric
just to note that our situations, experience and qualifications might be very different but i was granted a .22/.17/.222/.243.308 all on first aplication. within the last 5 years so it is possible to get what you want first time!