Among the factors that can affect your credit score are:
Payment history
Credit utilization
Credit history length
Credit Mix
New credit
See https://www.experian.com/blogs/ask-experian/credit-education/score-basics/what-affects-your-credit-s...
There are several credit scoring models and you can check your score via several methods, including signing up for Turbo --> https://turbo.intuit.com/
You should also review your credit reports (free from the site below) for inaccuracies.
https://www.annualcreditreport.com/index.action
