Hi Dan. Thanks again for your question and please don't worry. You certainly do not have to apologize for asking questions. While I am unaware of a way to lock down internet access to your computer like that, you would want to have your Guardian set up Screen Time restrictions on your iPhone®. It sounds like you are already at least partially familiar with that option on the iPhone®. If you are wanting to lock down your internet on the device then disable the Safari app within Screen Time by going to Screen Time, Content and Privacy Restrictions, Allowed Apps, and then toggle Safari to 'off'. Then delete all other browser apps that you may have installed. You will then want to have your Guardian toggle off the App store so that no more browsers can be installed. Be aware that Covenant Eyes® functions as a browser on the iPhone® so if you are wanting to remove your internet access completely then your Guardian may be looking into deleting the Covenant Eyes® app off of the devices as well. Otherwise you can simply leave Covenant Eyes® as the sole browser on the device. I will include a link below with instructions on setting up and utilizing Screen Time restrictions in case you need it Dan.
https://www.covenanteyes.com/support-articles/set-restrictions-ios-12/140