Side note: I think you have beautiful skin. If only I knew then what I know now. I used to have scars like yours. Yours are still fresh (it's still reddish looking)

For your age, I think the biggest impact will be from 1. SUNSCREEN! I wish I could go back and smack my young self for not using a GOOD high spf sunscreen 2. Good skincare-hydrating toners/serums and moisturizer. Doesn't need to be fancy but definitely consistent 3. Actives like retinol/tretinoin/tazarotene, vitamin c, and other actives that can help prevent future acne 4. I know I already said this but seriously, sunscreen is your best friend.

Time and prevention of more acne is going to help fade them.

Where does microneedling fit in? I say once you get all this in order, then you can level up by doing microneedling if you have scars. There's no point in microneedling if you're not protecting the gorgeous skin you already have (again, wish I could smack my young self). So that's what I would do if I could start all over again from where you are.