What should non-technical founders do to be more technically literate?

Actually, it's not too far-fetched to learn how to program on your own, especially if you pick a language that you know you want incorporated into your potential product (this is probably the first step to take). Medium is full of articles that provide step-by-step instructions for building a small project in various programming languages. For example, this is a good one that probably would take a day (or maybe an entire weekend if you have a busy social schedule):
https://medium.com/@deallen7/ruby-on-rails-app-build-blog-3d9975a999ae

I believe Ruby-on-Rails is a common language used for startups, and I find it pretty intuitive. There's also JavaScript as well, which may be the most commonly-used language I see on here.

Also, check and see if there are Meetups in your area that host one-day programming sessions. There was one where I used to live in CA that would go over HTML, CSS, and JavaScript at a high-level once a month on a Saturday. Those are generally good enough for you to get started and become familiar with the language(s).

I used to be non-technical and no-code was not really a thing back then. Then I decided I wanted to build something of my own. I made it my objective to be able to code until I can at least ship a reasonable product.

My first step was to find the tools to learn. I found out about Ruby on Rails after a quick Google search and followed tutorials on Udemy.com and Gorails.com. After building a few mini-projects, I felt confident that I can now build a full-fledged application from scratch. That's how I managed to build what I'm building right now with oneprofile.info

To be honest, I don't think I'm capable enough to build a product that can scale globally but at least I am now capable to ship a good product. Trust me, as you learn how to code, little by little the concept will sink it and the joy of seeing what you type on your keyboard comes to life is indescribable!

Good luck!