I may sound like i come from the dark ages but how exactly does Internet check-in work? Even though i have done a IT degree

I assume that we check-in and answer a few questions on-line on any links to the taliban. Then do we print out the boarding cards from our home printer? Are they in colour?

Then show the boardings cards at check-in and drop off the luggage? Is that it?

If thats the case then how long before departure do we need to be at the airport if we have checked-in? 30 mins?