Error displayed on dash?

Purchase the vehicle about 3 to 4 weeks ago is having giving me any kind of trouble or any signs of trouble in tonight with your friends house, but Janet my friends leaving and it won’t start so I thought it was the bad connection and the battery post was loss and corroded, so I clean the battery post and the clamps and proceeded to give it a jumpstart with another vehicle. It started with shut off, started and shut off again and happened again about four other times and then did the reading on the battery. It is giving 15 V we connected the battery and then it started and shut off and then shortly after it was just clicking and then the clicking stopped and then it did nothing no clicking no nothing.