Yes, you (your dog's best friend) are responsible for dog training and caring for him from the moment you welcomed him into your life as part of your family until death do you part.
Although your main purpose in dog training your dog is not to show off with tricks, I'm sure you won't be laughing like I did at Skip's every wrong move if instead of going 'potty' outside your humorous dog uses the carpet in the living room.
If you're going to get dog training help from a certified dog trainer get references from friends who have pets and make sure that you are comfortable with their dog training methods.
There are many reasons to start dog training early, including your dog's safety, and the preservation of your home, belongings, and peace of mind.
Dogs are sensitive, and the stress they experience being punished may just make problematic behaviors worse.
Also, catching your dog when he's about to do something naughty gives you a better chance of communicating your displeasure, whereas after the fact they are unlikely to understand what they have done wrong.