I am new to Google Analytics and I would like to track a first step of our customer. So for example Customer1 visited our page on 1st of January 2016 from google / cpc. And on 2nd of July 2016 Customer1 completed a conversion from source facebook / referral. GA takes "last step" as a completed goal but in our case is better to know a first step google / cpc.

I have just figure out that we can track customers by IPs but I read in GA terms that it is forbidden.

So this is reason why I made a question here. Is there some way how to solve this problem?