This is a fine place to post.

Use of a computer is optional. If you are a total newbie, you may benefit from a computer with cadence. You generally want your cadence to be 80-100 which seems too fast to many beginners.

That said, I don't use a computer and do fine without one. I do use the strava app in my iPhone, but I only use that to track mileage and only look at it after a ride. Up until last year I didn't even do that.

You probably want a basic computer that gives speed, cadence, and mileage. They are pretty inexpensive. Like anything else, it's a tool. Most folks who are more "serious" about their training make the jump to a Heart Rate monitor, or even a Power Meter.

What are your goals??