For those just starting out, it will be easier to buy chemicals separately. Then you can add EXACTLY what you need, when you need it, based on your own testing.
After you have the hang of all of the various chemicals and how to use the Pool Calculator, then you may want to begin using chemicals that are blended, as in trichlor, dichlor, or cal-hypo.... WHEN you know what the components are and how much of each you are adding and you understand the safe ranges of each chemical.
For example, in order to get your CYA up to the level you ultimately want, you would want to calculate the total volume of dichlor, then determine how much of that total you could add each day. It may take awhile. Easier to just by Stablilizer and add what you need, now, all at once. The chemicals won't be wasted, stabilizer will keep until next year or when you need it again.