Minimum connections to get online

I’m new to Comodo, and I know next to nothing about the technical side of computers anymore. But I’d like to set up my laptop so that nothing goes online except for what’s absolutely necessary to use the web. I don’t know enough to know what’s really required and what’s not, but I’m intimidated by the idea of various dlls running through svchost.exe having dozens of connections as soon as I connect to my router.

I don’t want all my software “phoning home” all the time to send usage data or whatever. I’d like to be able to set it up so that my web browser and antivirus software (Avast) goes online, along with whatever’s required to keep my connection from dropping out, but make everything else either be blocked automatically (so it acts as though I wasn’t online) or ask my permission at the time it wants on (so I could allow it if I were doing something where there was an obvious need for it to get online, like for downloading updates and stuff)-- but also not be constantly nagged by alerts where system processes want access all the time.

Is that possible? And if so, is it something someone could guide me through setting up?