What language should I use to build a custom pricing form on my website?

I'm a beginner, but willing to learn whatever is necessary to build a simple pricing form for my customers.

Essentially, the user selects from products I offer, enters quantities, and has the choice of a couple other modifiers. Then, they get immediate pricing based on quantity discounts, unit prices, etc.

I worked with a data scientist to write an algorithm for pricing, but now I need to learn to build the feature. I would love any recommendations on where to start. My skillset stops at HTML/CSS, but I want to use this project as an opportunity to learn new languages.