Pay your bill by check - they don't charge for that. Or by using your bank's online bill pay system.
Always pay your bill in full on time - that way you don't have any interest to pay. If you don't have the money to buy something - don't charge it. Wait until you can afford it. Buying on credit used to be called 'Buying on the never-never' in England. Because you never paid it off and therefore you never properly owned the item.
Credit cards can be very useful if used properly and carefully. Don't go into debt.
Good Luck!