Trouble to log in on App Store

I am having trouble to log in on my Macbook pro.

I recently changed my password (because every time I tried to log in to download from the App Store)

However, even after I changed my password, and type my password correctly, the message kept saying “An Apple ID verification code is required to sign in.Type your password followed by the verification code shown on your other devises.”

So, I typed the verification code that you guys sent me to my iPhone (six numbers) 

As I remember I have already gone through this the first time I log-in on the apple webpage on my laptop.

Then, now it says, “Did you forget the password?”

This happened again and again.

This is my first time to log in tot he App store on my laptop. 

Please let me know what I can do.