There is no correct length for coats, or skirts or dresses.

However trailing the florr is not a length. Coats can be ankle length or mid-calf or mid thigh or anywhere in between. Shorten it to a length you feel suits you. One that looks good on you and covers most of your skirts and dresses.

Then look the coat over. Pay attention to where the buttons and buttonholes are. You want a space at the bottom that does not have buttons. Look at the button and buttonhole plackets. Are you going to have trouble turning a new hem up or will you have to undo some stitching there.

Rehemming a coat is not an easy task. If you think you may have trouble then take it to a pro to hem.