Content is one of the most important thing as far as SEO is considered. One needs to have quality content on the website. As in your case you have very less content on the homepage and want the user to be redirected to this page, so you need to have the keywords that you are targeting in your URL, meta title, meta description as well as the content for maximum people to reach it.
I am building a website and looking to direct users to my homepage, where the call to action is. I have kept content to a minimum on this page, I am creating a lot of content on other pages of the website that is helpful to my users. My question is, does this content help with SEO of the homepage even though it is not directly posted on that page?