Hi Tejas. Yes it is normal for the fingers to hurt when first learning to play. Once your fingers get a little stronger and you develop callouses on your fingertips, they won't be sore.

The jack should be an easy and inexpensive (if not free) fix for any music store.

Sounds like you have a good plan for learning. Start with the basics. Our friend Robert here has some good video lessons, too.

The chord symbol on your tablature is there to let you know that the notes you're playing sound like they are part of that chord.

Welcome to the Fret, btw. Good luck to you.