You should check because mistakes happen, and they can cost you money. An error might make your credit score lower than it should be. Lenders use that score to decide if they’ll give you a loan or credit card and what interest rate you’ll pay. A lower score could mean higher payments. Checking your report is like proofreading your work before turning it in to get the best grade possible.

Two main things happen. First, each application puts a small, temporary ding on your score. Second, if you do get new cards, the average age of all your accounts gets younger, which also can lower your score. Your score likes to see a long, stable history. Opening several new accounts quickly makes your history look new and unstable.

The best first card is often a “starter” card made for people new to credit. Look for a “secured credit card,“ where you put down a small refundable deposit, or a “student card” if you’re in school. Avoid cards with yearly fees for your first one. Your own bank or credit union is a great place to start looking, as they already know you. The goal is just to get started building history.

Your score can drop almost immediately after you’re 30 days late. Credit card companies and lenders typically report to the credit bureaus once a month. If your payment is late when they send their report, that negative mark gets added right away. There’s usually no grace period once you hit that 30-day mark. This is why it’s so important to contact your lender the moment you know you’ll be late—they might offer a one-time courtesy.