You must be about 16. Still, no excuse for the ignorance. As Fr. Chuck stated in your OTHER question - you should not be driving because you have clue zero as your responsibilties.
To transfer the title from your sister to yourself does not take long at Motor Vehicle. You take the title, that your sister has signed off on, stating that you are the owner. There will be an amount that will show how much you paid - there is also a space to show it is a gift. You WILL pay to get the vehicle registered in your name - no freebie there. Motor Vehicle will process the information and you will receive the new title that day ( at least it works like that here in N.D.). Here they ask about car insurance and who the insurance carrier is. Sadly though, DMV does not verify the information, so any lying person can claim xyz policy and drive off.