Taxi your pup for about one month (until the pup is about 3 months old as this should give the pup enough time to develop some bladder and bowel control). By doing so, you will prevent many mistakes. At the same time you will train a stong preference in your pup to eliminate in your chosen spot. The pup will also learn that being picked up gets - kisses !
Don't allow your puppy freedom outside of his room or pen unless you know absolutely for sure that his bladder and bowels are completely empty. When you do let him out, don't let him out of your sight. It is a good idea to have him on leash when he is exploring your home. He can't get into trouble if you are attached to the other end of the leash. Never, ever tie the puppy's leash to something and leave the puppy unattended.
A training class is not there to train your dog. Its purpose is to teach you to train your dog so you will need to be committed to train your dog for short sessions (5 minutes) several times a day rather than just simply turn up for classes! This little bit of training everyday will be repaid with a lifetime of living with a well behaved dog. You will also learn to avoid problems before they begin as well as receive help to overcome any that you already have with your dog.