my instrument cable is a little ripped near the jack and copper is sticking out a bit? Im no technician, but is that safe? Should i wrap something around for the time being?
It's safe as the current going through it is almost unmeasurable. It's not likely to affect anything, but if it makes you feel better you can put some electrical tape around it. Some may say it's now more libel to pick up stray signals, but it was probably not insulated well anyway if it tore.