Credit Card Lounge

I want to get a frequent flyer credit card but I already have 3 credit cards with generous limits. I don’t need these credit cards and I would like to cancel them and have this “possible credit” to go towards the new card. I heard once that canceling a credit card has a negitive effect on your credit score. Is this true? If so, how do I switch credit cards and avoid affecting my credit score in a bad way?

There are lots of offers that give away free stuff for signing up for a credit card. Assuming that I just sign up, get the reward and then cancel, does that hurt my credit or anything else? Thank you

I had applied for an ICICI credit card. But now i want to cancel it.

i want to know that the fact that i filled it out ment that it was already appoved or that the account was opened? If i cancel it will it ruin my credit?