Avoid using too many serums immediately post dermapen. Most important to use a sunscreen, like Aveil SPF 50 GEL MORNING AND NOON. ALSO after 3-5 days use Aveil C-NU serum daily at bed time for 6-8 week for a good result in terms of skin brightening and even toning, also vitamin c serum is need for scar improvement for synthesising new collagen. Where are you doing dermapen from? What all have they suggested?  There are many other better treatments but more expensive for acne scars too like resurfax laser and some home use peels and serums.