The average age of your credit accounts is a factor when it comes to determining your credit score. So if you’re just getting started with Fizz, don’t worry. You just need to keep being responsible with money. If you can manage that, you should end up seeing gradual increases in your score to the point where you don’t need to worry about it at all.
If you’re missing payments, then this is probably the main reason why your credit score isn’t getting better. To avoid missed payments, enable autopay and make sure that you’re paying off your other lines of credit - other credit cards, loans
If you’ve ever heard the phrase “it takes 10 years to build a reputation and 10 seconds to ruin one,” it’s a good way to think about your credit. Your score isn’t increase quickly because building a good score takes time. Just make sure you’re responsible and your score will follow.