Thank you for the opportunity to help you with your question!
In order to have a credit score to begin with, you will need a credit card. As you may have learned, credit cards are essentially a way of 'borrowing' money from the bank. You will eventually have to pay it off since it was not your hard earned money to begin with.
The problem many make when it comes to managing credit is not being able to pay off what they borrowed by the end of end month. This leads to late payments, lowering credit.
The best way to manage credit is to plan out how much is going to be purchased with a credit card each month and being positive that it can be fully paid off on time. This will raise credit and will allow lenders to have greater trust in the buyer.
I like to think of credit in the same way as grades in school. In school, you need to study and plan out your time efficiently to get good grades. These good grades allow you to get into better colleges, because they can trust that you will be a diligent and hard working student. Similarly with credit, you need to plan out and manage your time to avoid late payments and build a good credit score. With this score, you have better choices when it comes to leasing a car, renting out an apartment, etc.
A credit card is merely a bank loan, not a gateway to free money.
Please let me know if you need any clarification. I'm always happy to answer your questions.