Did I get rid of the computer virus on my Samsung Galaxy J6?

It depends on the severity of whatever got you. It is possible the nasty can survive it. And Samsung doesn’t have the best record with Androids updates. And a factory reset is different from a nuke and pave on Android (iOS too).

But I am pretty paranoid. I don’t ever enter my credit card or banking info or even check my e-mail on my phone.

I think you may have to stop visiting sites that have know virus content like porn sites and pirate peer to peer sites.
Try putting Avast free for Android,

I think they have a Canadian version.