bad credit visa credit cards

Is it okay to cancel credit cards that you no longer want?

My friend told me that if you close a credit card account that you no longer use that it looks bad on your credit. Is this true? For example I just applied for a United Airlines Visa card that is free for 12 months. After 12 months the annual fee is $60 per year. After I have gotten my free flight I plan on cancelling the card after 11 months.
I have a Discover Card that I have had for 7 years. I have a Chase Mastercard that I have ahd for 4 years.

your credit score short term will show an effect for closing down these credit cards but it is usually just a couple points and no real major damage, but it comes back up within a couple of months after wards