"Getting a ticket," usually means you are "buying" it. If you want to go to the concert I will get the tickets. The line at the ticket booth is very long. Sit here, and I will go get the tickets. If you want to enter the museum, you need to get a ticket first. "Take a ticket" usually refers to you physically picking up a ticket from someone's hand or from a machine, or someone physically lifting the ticket from your hand. When you enter the theater, the usher will take your ticket. (You already bought the ticket. Now you must give it to the usher, who will "take" it from you.) Put your money in the machine, and then take your ticket from the slot. You're going to the airport. Don't forget to take your airline tickets with you.

Get a ticket may refer to you buying a ticket. Take a ticket implies you’re picking it up. However they can be used interchangeably sometimes.

Hi. They are the same...