It takes quite some time to train a dog, regardless of whether it is an older dog or a puppy. If you want to know how to train your dog, then the first commands that you should teach stay, sit, come, lie down, and say No. You must start with sit-stay-come-lie down in that order. Most dogs learn the "No" command with house-breaking, but it requires a lot of reinforcement.
You must be very consistent, and committed, and train your dog at least daily for thirty minutes and ensure that you give it some little time to play after the training sessions. Train a dog how to sit, requires some dog treats, a six-foot lead, and patting the dog gently on the rear as you say the sit command. If the dog sits, pamper him/her with some treats.
Then proceed to walk a couple more feet with your dog, redo the command, press the rear, and give another reward. You must keep doing this on a daily basis until it masters the command. Once the dog knows how to sit, the next command is to stay. You proceed by using the same lead and tell the dog to sit. Once the dog is sitting, you can give the dog a reward and say, good girl or boy. Next, put your hand on the stop position of the lead, ask the dog to stay, and walk gradually back say four feet as you hold the lead.
Give two minutes and walk back to the dog and shower with some praise and a reward. Do this several times on a daily basis and increase the number of feet between you and the dog each time. After one week, drop the lead and command the dog to stay as you walk at least thirty feet away from the dog and out of sight. After the dog learns how to stay, then teach him the come command to do this like just use the lead and ask the dog to sit and stay. Then try walking a couple of feet away and ask the dog to come as you gently pull the lead. If the dog comes to you, give a reward and repeat this command as you increase the walking distance to around forty feet.
The easiest command to teach a dog is the "No" command. Every time the dog does something wrong, point at the dog and say No. Most dogs are familiar with this command though some may not really understand it.
To understand this command better, most dogs learn by house-breaking. To make the dog lie down, just tell it to sit, and then lie down as you place your hand on the ground or floor in front of the dog. If he or she learns, then give a reward. This is also an easy command and can be learned alongside the stay command.
You should never shout at the dog while you are training and always be consistent with the word you use when giving commands. Keep repeating the commands as the dog gets older in age, as they may forget and start disobeying.