I agree with almost everything said in this post.
Getting a puppy is a HUGE commitment, and will be very difficult if you are going to be a summer associate out of town. It's much easier with a roommate or even a friend nearby who can help you during the day.
I understand the burning desire for a pet -- I wanted cats for years but had to wait because I lived on campus as an undergrad and my 1L roommate was allergic. The week she moved out I adopted 2 kittens from a shelter and couldn't be happier. They are a big responsibility (food, scooping litter, vet bills) but it's well worth it. However, I don't have to worry about training them to go out, and they can be left alone for much longer amounts of time if needed. Most apartments are also more accepting of 2 cats than a large dog.
Right now might seem to be a great time to get a puppy but I'd caution you to wait a little longer. Figure out where you are aiming to be your 2L summer and after graduation and how conducive a dog will be for that lifestyle. Think about getting a roommate. A puppy will be very time consuming and your 1L grades are very important. It might be best to wait until after your 2L job search is over (you might be flying to interviews multiple times a week -- who will take your dog out?) -- which will also let you better establish your future plans.