The cable should exit straight from the shifter body. Your cable is bent 90 degrees and it appears strands are broken. You will have to determine that for yourself. You can buy a cable online or at a bike shop. You will need to cut it to length and will need to adjust the tension after you replace it. In all honesty, since you are unable to use the excellent Park Tool site to answer your questions, I have little hope that you can complete this repair. Take it to a bike shop. Lots of folks don't do their own repairs, for a variety of reasons.