If you are in debt and/or seeking funding in fiat money, an important step is to get a good picture of how the credit bureaus view you. A credit report will help with this, because it shows all the information that parties seeking to trust you will look at. The items on the credit report are tallied up to create a credit score. The credit score will come from 1 to 3 credit bureaus (Equifax, Experian, Transuion) and the scoring model used to create the credit score will be FICO 8 or Vantage 3.0. The model that matters most for funding purposes is FICO 8. FICO 8 scores will typically be 30-50 points higher than Vantage 3.0.
The best free resource for someone completely new to credit scores and reports is the Scorecard by Discover. The reason for this is that it is a simple single-page site which shows you credit score in the first tab and then shows how you stack up in each of the 5 areas used to create the credit score in the next tab:
So, once you have a good birds-eye view of what your score is and how you stand in each of the 5 categories that make up your score, it's time to go deeper. And here are good resources for that:
The most widely used paid resources for credit reports are: