Are there any good resources for first generation/low income students?

Besides Questbridge, there is Posse (possefoundation.org).

Also look at the Coco-Cola scholarship, the Gates Foundation Scholarships and the Jack Cooke Kent scholarships.

QuestBridge is obviously the big one, but I would also look into federal and state financial aid programs. In particular, look into your eligibility for Pell Grants, as depending on your income level you may be able to get money from that program put towards your cost of attending college.

Separately, when you search through schools to apply to, focus on two categories—in-state public schools and private schools that guarantee to meet 100% of your financial need with their need-based aid packages. Private schools that don't do that will likely remain too expensive to attend, and out-of-state public schools, outside of some kind of tuition reciprocity program (like a school that gives in-state tuition to students in neighboring states), will likely be just as expensive.

There are other good resources listed here: https://www.edumed.org/resources/low-income-students/, which you may have already seen. One note though—focus on earning grants and scholarships directly from your college or from financial aid programs like the Pell Grant; scholarships from private organizations and companies are rarely worth the time you need to put into applying for them, as they're typically very small relative to the real cost of college.