Hello. I'm not really familiar with melanoma. But here's a booklet from the National Cancer Institute http://www.cancer.gov/cancertopics/wyntk/skin.pdf
or you can also order a free copy of that here https://pubs.cancer.gov/ncipl/detail.aspx?prodid=P196
The American Cancer Society has information here http://www.cancer.org/Cancer/SkinCancer-Melanoma/index
No sense worrying about the past. We don't get an owners manual when we're born, and we learn as we go.
If you check with local hospitals, they might be able to direct you to free skin cancer screenings where someone can help. You would need a computer program, or schedule and good record keeping system to track that many moles and measure change over time. I don't think that's very practical. They probably just mean to scan over your body and see if any of those characteristics they define stand out at you. That's a good question for one of those websites.