you will go to your unit. many of the people from my company had gotten stationed at op 4 units the rest are going to afganistan in a few months. and befor you go to your basic training company you will be told if you are 11b or 11c. people from my company that had 270 on thier pt test were also givin the chance to go airborne or airborn ranger
I'm not Infantry but from my experience you will spend your free time training,PT, qual ranges, PT, skills improvement, PT, attending schools like Combat Lifesaver, PT, Weapond Maintenance, PT, Field Training Exercises, More PT
No one holds the MOS of 11X past OSUT. USAR does have Infantry. You should probably read this page: https://www.goarmy.com/careers-and-jobs/browse-career-and-job-categories/combat/infantryman-11x.html Aren't you in the USAR?
You could not enlist as 18X. 18X will not allow anyone who requires a waiver. You can always request SFAS later on, but you'd need a score waiver. More likely, you'd be told to take some ASVAB improvement courses and retest.