Remember that training is an ongoing process. You will never be completely finished. It is important to keep working on obedience training throughout the life of your dog. People who learn a language at a young age but stop speaking that language may forget much of it as they grow older. The same goes for your dog: use it or lose it. Running through even the most basic tricks and commands will help them stay fresh in your dog's mind. Plus, it's a great way to spend time with your dog.
Effective dog training does not require many items, but there are a few basic supplies that will help make the process more convenient and effective. Choose a dog collar or harness that is suitable and comfortable for your dog. Then decide which dog leash is best for training. A retractable leash is not appropriate for dog training. You will also need dog training treats that your dog enjoys and are easy to eat quickly so the reward is more immediate. There are plenty of great treats available at pet stores or you can also use something you make at home, like small pieces of plain cooked chicken or turkey.
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.