Is a 658 credit score ranked as fair or good?
Before answering this question, you need to apply the proper credit score range, which for Fico is 300-850 and for VantageScore, is 501-990.
We'll assume you're referring to Fico, as it's the most commonly used credit score out there.
A 658 credit score would be defined as below-average credit, or perhaps fair. It's certainly not good, as credit scores upwards of 660 are only average.
If your credit score is in this range, you probably have a late payment or two, as well as high balances.
The best way to improve your credit score is to pay off high balances, make on-time payments, and apply for new credit sparingly.