Hey! No dumb questions here 
So, as stated here, environment variables that are available during the build process [such as those in the UI] won’t be available to your client-side UI unless you interpolate them at build time. Some frameworks do this for you automatically. For 11ty, you’ll need to expose them.
We have a great write-up on how to use environment variables correctly which may also be useful!
TL:DR; it’s doable !