Ko-fi doesn't handle the money that is sent. The payment is made from your supporter, directly to your PayPal. Often payments go into a Pending state in PayPal.
There are many reasons for this. Sometimes it's when one of the PayPal accounts are new, it will take a few days to complete. When PayPal completes the payment, the coffee and message will show up in Ko-fi.
If your Payment is in Pending, the first thing to do is log into your PayPal account and check to see if there are any messages. Sometimes you will need to confirm your account or email address before PayPal will complete the transaction.
Another thing to check is if the PayPal email address you entered in Ko-fi is correct and assosiated with PayPal. If it's incorrect, PayPal will normally keep trying for 30 days after which the payment will be returned to the sender. If you used an email address that you own, but it isn't associated with your PayPal account, you can still associate it with your PayPal account as a secondary email address. If this is done within 30 days, often this will be enough to receive the funds.