Answer:

Your best bet would be to purchase a "starter kit" (maybe one came with the pool) that usually would have everything you need for at least start up of your swimming pool. Pool stores in your area will customize starter kits based on the region that you live in because the water there will behave similarly to the other pools in your area. A good starter kit will also include a good reference book and trouble shooting guide that will help you with what to add. There are also "start up" guides online that can help with what to add to get started. However, be aware of the self-serving start up recommendations that come from a manufacturer recommending their specific branded products.