Aren't you sure what you should get in COSRX ?
Don't worry :D K-SECRET suggests the basic 3 step items (Cleanser > Toner > Moisturizer) that you can use on a daily basis. These items are suitable for all skin types and very good as a daily skincare product as well.
COSRX uses minimal ingredients for maximum function.
-Daily Cleanser : Low pH Good Morning Gel Cleanser
Formulated with botanical skin-purifying ingredients. It works softly to make skin supple and clear.
-Toner : AHA/BHA Clarifying Treatment Toner
Exfoliating,Moisturizing diminishing blackheads and whiteheads.
-Moisturizer : Hydrium Moisture Power Enriched Cream
Moisturize in your own way With Hydrium Curation made exclusively for you.
Volume
Low-pH Good Morning Gel Cleanser 150ml
AHA/BHA Clarifying Treatment Toner 150ml
Hydrium Moisture Power Enriched Cream 50g