Welcome to TFP!
Do you mean what is best to use with regard to treating the pool chemical wise? All the products we use are common things like Bleach (AKA liquid Chlorine,) Muriatic Acid, and sometimes Baking Soda (Sodium Bicarbonate) for certain situations. The uses for these, or other products are discussed at length in Pool School. Begin reading there with the ABCs, and start working through the other articles. Ask all the questions you might have here in the forum, and there will be plenty of folks who'll enjoy helping you through. You can find Pool School at the top of the main page, or by clicking the links in my signature.
As for leaving the pool empty, it's not good for the Plaster, or other finish you may have, particularly once it gets hot. The sooner you can get it right and holding water, the better.
Are you getting close to having it repaired?