Outdoor activities make our skin tan. The only option is to wear protective full sleeves clothing, cap or a hat, to carry an umbrella and sunglasses.
Skin already tanned can be treated with depigmenting creams.
A good skin care regimen comprises 4 steps - cleansing, toning, moisturizing and sunblock.
Based on your skin type, a dermatologist will recommend you appropriate products.
Sun protection is mandatory and will require usage of Sunscreens. You may benefit from usage of a Laser device i.e. Q- switched N d YAG. Internal health needs to be fixed based on blood chemistry reports.