If you're going to train your dog you should understand that no matter whether you train a puppy or a older dog it will take time. I think the first commands that you should teach.your dog are come, lie down, no, stay and sit. It's best to start with sit, then move onto stay, lie down and then come. The command "no" might need reinforcement but most dogs can learn this command while housebreaking. You need to be consistent and train your dog daily for at least 30 minutes per a day. After you've trained your dog each day, there should be a little playtime. 

In order to train your dog to sit you will need small dog treats and a six foot lead. The first step is to pat your dog's rear as you tell them to sit. Now when your dog responds and sits your going to reward him or her with a dog treat. Your next step is to walk the dog a few feet and then repeat the command while you are gently pressing down on their rear. Again your going to reward them with a dog treat if they obey. This training should be done every day for atleast one week until the dog knows and performs the command. 

Once they have learned to sit, the next command you must teach them is to stay. For this command you are going to use the lead, and tell your pet to sit. When they sit, say good girl or boy and reward them with a small treat. Your next step is to put your hand up in the stop position just like a crossing guard does, and tell them to stay. Then gradually walk back about four feet while your holding the lead. After two minutes have passed, then walk back to your pet and praise with a treat. You can repeat this step by gradually walking a full six feet and returning. After a week it's time to drop the lead and command them to stay while you walk thirty feet away. Once they have that down you can practice walking out of sight. 

The next command that your dog is going to learn is come. To teach your pet how to come your going to use the lead, tell them to sit and stay. Again you will walk another full six feet away and tell them to come while you gently pull on the lead. When your pet comes to your side they should be rewarded with a dog treat. You need to repeat this step and gradually work the distance until you reach forty feet. After they have this step down, leave their sight and when you reappear, ask the dog to come and reward.

Ok the next one is the no command and it should be easy to do. When your dog is doing something wrong, say no and point your finger at your pet. Im sure you have always used the no command with your pet, but some dogs do not understand what is meant by no.

Ok the last command I want to talk about is the lie down command. The lie down command is done by telling them to sit then telling them to lie down while placing your hand down to the ground in front of them. You must reward as the dog learns and does what is commanded. The lie down command is usually learned quickly and can be used with the stay command.