Sometimes, you may receive an offer for a free trial period.
I’d expect this to be the most common scenario that matches what you’re talking about.
Make sure you understand what it’s telling you before you provide any information.
And of course, remember to explicitly cancel the service after the free trial period is over unless you really to want to continue and pay.
The more cards you have, the more you will need to keep track of, so having just a few can help you simplify your overall credit card management.