It depends on how deep the scars are. If they're really superficial, retinol might help you more than vitamin C: it speeds up cell turnover and smooths out your skin over time. Two months is actually still pretty early, especially if you're not using a targeted product. Try introducing a lightweight retinol (like 0.3% to start) every other day and see how your skin reacts over the next few weeks.
For the red marks, the key thing is protecting them from the sun because it really makes everything worse. Using good sunscreen is more important than it seems. If after another two or three months the retinol isn't enough, then you could look into more serious treatments like microneedling or laser, which really do speed things up.
One thing I see a lot of people underestimate: patience. A lot of people switch products every two weeks and their skin doesn't have time to respond. Stick with a routine using retinol, vitamin C, and sunscreen, use it for at least 8-12 weeks, and then see. If it really doesn't improve by then, that's when it makes sense to ask a dermatologist in person because they could suggest something more targeted.