As others have said, you do not have to pay high interest
for using a credit card. But the credit card companies try
to get you to pay interest with a variety of tricks. Many
people have no idea as to how credit cards work, and so
fall for these tricks.
If you have a credit card, the card companies emphasize the
minimum payment that you have to make to keep your account
"in good standing." Lots of people like the idea of keeping
their account in good standing and so happily make the minimum
monthly payment. But what happens is that once you do so,
interest starts getting charged on the unpaid balance
every month until the unpaid balance is reduced to zero.
For lots of people, this means never and so they live their
lives in the belief that using a credit card means paying
high interest: they have no idea that a different modality
of existence free of credit-card interest is possible.
If you ignore the credit card companies'
blandishments and pay the total amount of the monthly
balance every month by the due date you will not be
charged interest: no interest at all if you follow this
practice each and every month after you open the account.
But if you have been carrying a balance and decide one
day to pay off the balance in full, there will be a minor
hiccup of one month when you will be charged interest again.
Don't fall off the wagon and resume your bad habit of
making the minimum payment or partial payment each
month because of this hiccup. Keep at it and
religiously pay off the full statement balance every month
and you will not have to pay interest again.
Your question in the comments about one-year waivers
also has a double meaning. Many credit cards come
with annual fees, and some of these are waived for
one year. Many other cards are available without
any annual fee too. If you have no credit history,
you might not qualify for some of these, but look
around: your local bank might be more helpful
than a large issuer like Citibank. The other kind
of one-year waiver is for a "Transfer your balance
now and pay no interest for a year" deal. There
usually are charges for the balance transfer that
are not called interest, but are in effect prepaid
interest. There also are "Use these checks like
cash to pay your other bills" that are actually
cash advances on which you pay interest.
Be very
cautious in accepting such deals.