Grant Application Plugin Recommendation

I would suggest taking a look into using a forms plugin such as Formidable Forms https://formidableforms.com/, WP Forms https://wpforms.com/, Gravity Forms https://gravityforms.com/ for this and building on top of that if you need functionality that is not provided by the code base of the forms plugin you choose to use.

You may also need to us a membership plugin such as Ultimate Member https://ww.wp.xz.cn/plugins/ultimate-member/ to get some of the member functionality you are looking for.

Hope this gets you headed in the right direction. Once you find a solution you are happy with please tag the thread as resolved.