I just purchased a Roku Streaming +. I'm totally new at this kind of stuff. I was under the expression that a Roku turns your TV into a Smart TV. Are we able to stream the internet thru the Roku?
A smart tv has some apps built in, or later downloaded and installed on it, that can stream programming from the streaming service associated with each of the apps.
A Roku does the same. You install one or more of the available apps, and you can stream programming from the service associated with each app.
Some apps let you stream free content, although most (maybe all?) of them are ad-supported with unskippable ads (maybe a ton of them).
Some apps you can pay to subscribe to, such as Netflix, Prime Video, and a host of others.
Some apps, associated with cable-type channels, will require you to have a paid subscription to a provider that carries their cable/satellite version.