Your credit score can be thought of like your grade. It is a score credit agencies use to rate you against others on how you will do paying back your loans or credit.
First thing you must know that this is a very bias system. It is system that reward people for taking out lots of credit and being able to pay it off. So those with higher income are more likely to have better scores which doesn't mean they are more worthy.
Luckily for all of use we can play the game in our own way and use the system to our advantage. The first and most important thing to always pay your bills on time which should be easy by setting up auto payments. Second is to work on reducing or better eliminating any balance carry over. This can be difficult, but should be everyone's goal. Last is history. The length you keep a credit card open the better. So if you have a couple of good card or you have one you have had forever keep it open. If these card don't provide much in the terms of rewards just put the cards in your socks drawer and get them out once very 6 months.
Keeps this up and your score will increase and will help you get the great rate for a home load. Some will say all debt is bad. That is true, but for 99% of us loans are part of life and since our world requires them we will use this tool and make them our own.