Brief Answer:
Avoid sun light exposure on face.

Detailed Answer:
Hi

Thank you for asking HCM

I have gone through your query. First thing you should do is avoiding sun exposure on face. Using sunscreen is good to avoid sun tanning. Use cap to avoid sun exposure on face while going in sun also.
Natural measures like using aloe vera juice , honey , diluted lemon juice etc on face is also good to whiten the skin.
Taking vitamin C and E supplements is also good.
Skin whitening creams you can use one based on kojic acid , vitamin e and vitamin C. This is considerably well tolerated when comparing other skin whitening creams. Start with little and see whether you have any allergy to the contents.
Using masks based on glycerin and honey weekly twice is also good.
Take more plain water to hydrate your skin. Take citrus fruits and greens in diet to provide enough antioxidants.

Let me know if anything not clear.
I am happy to help you.
Thanks.

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