acne scars

For breakouts:

Benzoyl peroxide (kills bacteria)

Salicylic acid (clears pores)

Sulfur (dries deep pimples)

Retinoids (prevent/treat acne)

Niacinamide (calms + reduces oil)

For scars:

Azelaic acid (fades spots, smooths skin)

Vitamin C or alpha arbutin (brightens)

AHAs (exfoliate, improve texture)

Retinoids (help fade scars)

Silicone gel (for raised scars)

Pro options: peels, microneedling, lasers, or prescriptions if it’s severe.
And always use sunscreen!

is there any I can’t use while breastfeeding ?

I'd say retinoids (retinol, tretinoin, adapalene), oral acne meds (like Accutane), high-dose salicylic acid, hydroquinone.
Of course always check with you gp to be sure.