diffrences between leads and sale?? how to know where links are from?

Hi guys, I got into HULU+ program at CJ. Im not sure If I got this right, I ve been 3 days at CJ and I generate around 1 200clicks and 6 sales, offer is paid for sale. My question is how to understand clicks here? when visitor get to LP via my link its counc as a click ? and if he clicks further at this LP its lead ?
2nd question, is there a chance to see where the traffic coming from into CJ ?I got 3 sites linking to one offer (the same links) and I would like to know which site gets the most clicks.

I would appreciate some help

for 2nd question, you can use different SID for different sites.