What do you know about Upromise?

As a graduating senior, I’m trying to save up as much money for college as I possibly can. I know that Upromise is a common resource for this, and scholarship websites frequently recommend it. But I am, of course, concerned about the safety of using it.

Is Upromise a safe and effective way to save money for college? An addition, is it legal for me, as a 17-year-old minor living in Maryland to sign up for it? The site does not give a minimum age, simply asking if I “am a person of legal age in the state in which I live,” and I do not know what the legal age for this is in Maryland. I would imagine that it is 18, but I am unsure of where to find this information. (Yes, I have a personal checking account and debit card, and I commonly shop online.) If I cannot legally sign up, would it be beneficial for my college funds for my parent(s) to sign up?

Any information or advice is appreciated!