Javascript. You can build out something like this in 10 minutes with GPT writing your Javascript/JQuery

Cashyourflow.com

You’ll get the hang of pricing as you do more projects. If you’re going to start with volunteer work, just let them know before you start that they’ll be responsible for the ongoing hosting (let them know the current cost of a webflow site plan) and then any maintenance needed from you will be paid.

When you’re going to start charging, you can use cashyourflow.com as a baseline then adjust from there depending on your gut feeling and what you know about the project.

You’re worried about turning away clients you don’t want anyway.