Is there a way to pass user data on home page to Cart Notes at Checkout?

I’m using the debut theme.

My store will be renting school uniforms. As there are way too many schools (in the UK) I am trying to think of a work around solution outside of creating a collection for each school.

As a workaround solution, I was thinking if I could have a text field (that autocompletes with real school names) on the homepage then having that data passed onto me in any way would be acceptable. I was thinking even something as ‘hacky’ as the school name user input being automatically placed in the cart notes is good enough for me. I don’t really care about my inventory being super granular.

I know it would be possible on a regular website to pass user input data from a text field to another page in the user journey. I am wondering if a similar thing could be done on Shopify?

Thanks.