Would sunscreen be okay and if it is what about my foundation?
You do not need antiageing cream at the age of 20 years .Certain skin care tips can be extremely helpful. Use a moisturizer with SPF 15 or 20, which gives you both UVA and UVB protection. Apply it all over your face and on your neck and chest. Use a hydrating fluid or an oil-free moisturizer. See a dermatologist. The doctor will prescribe what will be best for you. Do keep me posted.
Best luck and regards!