Guys I am in my early 20 what kind of serums I have to started using

Serum

How much percentage of niacinamide is best for everyday use

Niacinamide

Best cleanser ever for oily acne prone skin

How many times I should use niacinamide serum vitamin c serum and others and what time I should use what kind of serum like am pm

Amazing keep my lips hydrated as well as pigmented free

Nothing bad I could find it is an amazing lip mask

Amazing holy grail so much moisturizing and remove dead skin 