I'm 18 and currently my credit score was 524, only because theres an overdue bill of $500 from when I was a minor in my derogatory marks. I have disputed it through credit karma for Tranunion and it dropped to 0, but it didnt dispute it with equifax. So if I try to dispute it it brings me off credit karma. I'm currently lost on whether to dispute it or not, also I need good advice for me to build credit.
When doing anything sensitive with financial information, or just in general, it's always best to go "straight to the source" when possible. Instead of following links or calling arbitrary numbers, I always try to look up contact information directly. The dispute process for Equifax is available directly on their website.
In terms of building your credit, it's important to keep your end goal in mind. A good credit score, in and of itself, isn't going to change your life directly. What will change your life is making good decisions about how to use credit, if and when you need to. The credit score is a means to an end - it can help you qualify for a loan, and/or get a better interest rate on a loan. But whether or not that loan makes sense is another matter.
Credit scores are essentially built to show a consumer's risk of defaulting on a loan within the near future. With that in mind, the scoring factors used are based on behaviors that indicate financial habits that could lead to a default. On the one hand, you can spend hours or days researching via Google on how to "game" your credit score into a higher number, but on the other hand, if you use credit responsibly, the score will take care of itself. So, rather than focusing on trying to improve your score, make sure you're focusing on learning good credit habits, and your credit score will take care of itself.
With that in mind, It's hard to give specific advice about credit scores without knowing many details of your history and current situation, and what your near and long term goals are. The best way to get personal advice is probably to work with a financial counselor. Many local banks and credit unions will offer counseling as a free service, and can help teach you about other topics (budgeting, for instance) rather than just focusing on your credit score. It may make sense to try to find an institution local to you that can help you with these things. Typically, smaller community banks or credit unions with a focus on their members/customers will be more apt to help you with this than giant mega-banks who are only interested in their shareholder's profits.