You'll be great and chances are you won't have to worry about drafting vs passing at all. Drafting is not usually called unless it's blatant, as long as you pass withing 15 sec of entering the draft zone, you're fine. The only tricky part is dropping back out of the draft zone if someone passes you. Even if they slow down, it's the person behind's responsibility to avoid drafting.
Have fun!!
Living life like there's no tomorrow.
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2007 Look Dura Ace
2010 Custom Tonic cross with discs, SRAM
2012 Moots YBB 2 x 10 Shimano XTR
2014 Soma B-Side SS