Freelance: Think it was Elance. I knew Crystal Reports well. A client had a familiar problem, which I knew was a 'dll-hell' issue, fixable in a couple of minutes. Client had listed as fixed-price for $250 (those were the days 😁).
Fixed it very quickly on a call, got my first 5-star rating, too. However, due to the vagaries of international banking at that time, the payment never hit my account. In fairness I had a decent job and didn't strongly follow-up the missing payment, although I recall no response from Elance.
It still whet my appetite though, and later on, after a full-time permie & contracting life, when Elance became Upwork, my sole little 5-star rating did help me pick up freelancing jobs, and Upwork life became good.
First Paying Job: I only consider it helping out, but it meets the criteria. My Dad was a builder, and took me on a few summer jobs in between my later school years, as a labourer. Earned the princely sum of £30 per week.
Asked me at the end of the second summer stint if I was going to join up with him as a father & son team, to which he received a quite abrupt and tactless "No", and that was the end of that 😁