What qualifies as a first generation college student? I'm not sure if this is the right place to ask this so I'm sorry if this is not.

I'm in a bit of a unique situation in that I am turning 17 this year and will soon be adopted. The person adopting me has a college education but from what I understand, the first generation college student is someone who's legal guardians have not gone to college but also exists to help those who enter college with a limited understanding of the jargon, traditions, and patterns of expected behavior.    My birth father left my mom and me when I was 3 and my mom never got a high school education in order to provide for her family and later me.  My question is then, do I qualify as a first generation college student because I believe I am everything it is except I will have a step father who has a college education.
This is an extremely reasonable question, and the short answer is: what qualifies a student as almost any 'special box' in academic forms is a bureaucratic nightmare of conflicting interests, fuzzy or non-existent definitions, and what can in the end amount to guesswork - to the point that in the end the answer is that it depends on who's asking. There are apparently no less than three definitions provided used by the Department of Education. It's a mess.

Ultimately the only answer I can give is to check with the organization you are filling out forms with (University or otherwise) to clarify what they mean. It seems like common undergraduate admission apps use the definition of birth/biological parent having ever attained a college degree, but undergraduate admissions is generally off-topic here, so I'd still advise you to check with someone like an admission's officer or official program materials to see what their definition actually is. This is true for all future readers, as this technical definition may change in the future.

Note that for scholarship or diversity statement-related purposes, regardless of the technical definitions used, you are encouraged to mention your specific background in your own words, so you are not restricted to exactly what they mean by their terms.

I realize translating academese/legalese of this sort is a challenge generally, but this happens to be an area that is unusually difficult because there is no settled consensus and the definition of terms, and how they are used as decision factors, remains a hotly debated political topic (all the way to The Supreme Court, in fact).  

Good luck in your educational journey!