This USPTO web page provides general information about assistance for inventors:
https://www.uspto.gov/learning-and-resources/support-centers/inventors-assistance-center-iac

This USPTO web page provides information about volunteer patent attorneys and agents who work with financially under-resourced inventors and small businesses to provide free legal assistance in securing patent protection:
https://www.uspto.gov/patents/basics/using-legal-services/pro-bono/patent-pro-bono-program?MURL=ProBonoPatents

This USPTO web page provides a current list of law school Intellectual Property (IP) programs.   These Law School Clinics provide the opportunity to have a law student, under guidance of the program Administrator, consult with you about your Product and in many cases provide free assistance with filings:
https://www.uspto.gov/learning-and-resources/ip-policy/public-information-about-practitioners/law-school-clinic-1

The $10,000 Amber Grant is awarded by WomensNet every month, in addition to a $10,000 Business Category Grant and a $10,000 Startup Grant: https://ambergrantsforwomen.com/get-an-amber-grant/

Grant Watch is a repository of information for all manner of grants, including links to Grant Writers to assist with your application:
https://www.grantwatch.com/

Grants.gov is an official website of the United States government that provides information for very specific types of grants, but some small business grants are listed if you search for them:
https://www.grants.gov/