as an ignorant user, I would just like to have a browser setting such as 'only talk to sites using TLS'. I would be happy to deal with the fallout. does chrome or other browser have that?
The EFF's 'HTTPS Everywhere' Firefox addon [1] has a setting to block all HTTP requests. This is not enabled by default [2], but when turned on, will exhibit the behavior you want.
[1] https://addons.mozilla.org/en-US/firefox/addon/https-everywh...
[2] https://www.eff.org/https-everywhere/faq#faq-When-does-HTTPS...?