When you think about owning a dog, they are a lot like children - they want your time and affection, actually they NEED your time and affection. They are part of your family and they are totally dependent on you to meet their needs, including food, water, medical attention, personal attention. Adopt a dog is honorable because their are so many dogs in rescue kennels that have become too much for their owners to handle and care for. Your dog is your friend, your partner, your soul mate - he/she needs you as much or more than you need them. The responsibility is not a lot less than your own child. Keep that in mind.My parents would probably keep it until i had a home and a stable economy.
I have had dogs all my life, from Poodles, to Dalmatians to mixed breeds to yorkies. They all have personalities just like people but can't tell you what they need. It's up to you to read their signs and talk to your vet about feeding. An obese dog has a shorter life and requires more medical care. Keep in mind Labs shed - and note if that could be a concern.
Best luck in selecting your next all-time best friend!