Credit Score Management

Basically, my mom is going to be looking into buying a house soon. She wants to check her credit score. Which score is the actual one necessary to check? I’ve seen FICO and all types of other general “credit scores” that could be checked.
Which does a mortgage company look for, and just how many different “types” of credit scores are there? I know that a credit score is a summary of the creditworthiness based on one or up to all three of your credit reports. But where is the safest, cheapest and most reliable place to buy a credit score online?

I am selling my house (it was an investment property that I am flipping) and using the proceeds to pay off credit card debt that I have incurred while redoing the home. After the house is sold all my cards will be paid off and the only things I will have to make payments on are my car and student loan. I was wondering how long it will take the credit card companies to say the credit report of their zero balance status? Can I question the credit card companies to report the paid off status to my credit report immediately? Also should I close most of these cards or close them? How should I choose which credit cards to close and which to keep open to keep a high credit score? ( I have never had a 30 day late on any of my cards) I want to do whatever I can to improve my credit score the most.

Credit is terrible, can any one tell me if credit repair services really work.

I get my free credit report every year. I need to know how I can get my free credit score I’d appreciate any excellent answers someone can teach me, how to get free credit score report.

What is the most significant component of your credit score? What percentage does it add to your total credit score?