He's not too young, I cut my 15 week old's nails all the time. Start by desensitizing him to it by playing with his toes and feet all the time, gently pinch his toenails with your fingers to get him used to it. Keep plenty of treats handy. Mine don't love it, but they tolerate it. You CAN have a groomer do it, but you really need to start now and work with his feet, mouth, ears, etc. So that he more readily accepts those things if he needs procedures etc. done in the future by vets or groomers. Not working with them and then expecting a groomer to have an easier time, won't really help. The dog will be MORE stressed at a groomer and having someone strange touch his feet. Just work with him with that and start slowly. Do one, give a treat, do another, give treat, etc. Do a nail a day if you have to until he more readily accepts it, with lots of treats and praise.