Credit Score Management

I just turned 18 this week, and I want to know how can I start building my Credit score. Should I get a credit card from a store like Macy’s, etc. And how does the credit score works?
Also how much would i pay monthly, if i spend like 200 per month, how much would I have to pay?

I want to raise my credit score and get rid of a few items on there. I read about repair services. Do they work or will it be a waste of my money?

How can I check my credit score without credit card?
I know there r many sites which says that just give credit card # and its free for 10 or 30 days, BUT I don’t have a credit card and I wanna check my credit score immediately.So what r the options?

I need help as were to start off…… I am looking to open a credit repair business (Texas)
But I dont know what the law is regarding this type of business
, Is there any special training or licensing required?
any education (classes)?
Is this regulated by a specific office?

My credit score is 628 (not too excellent I know). But, is my credit score excellent enough to be approved for a student loan? I do not have a cosigner so that’s not an option.