As long as you have the 6 mandatory mod (CBA, TFAR, 506th, RHSUSF, RHSARFR, and All-in-Arma-Terrain) and have the two maps mods (SMD_A3 & Podagorsk) you wont be wasting a second at Recruit training when the instructor(s) speaks about the 506th. My Day One (for 30mins) was checking up on the condition of the mods and making sure people joined in.
Just like PV2 Padgett said, make sure your TFAR plugin are in correctly and checked in TS3 correctly. Do it manually; I think Arma3Sync does it automatically with repository, but just to be sure, check it manually in your folder and TS3 options.
Other than those 8 mods, you shouldn't have anything else in a collection to launch ARMA 3 for the 506th, unless told otherwise by your instructor or higher ups.
Continue on hard RCT Sharkey!