Had holiday gathering with multiple family members and found out that many had skin cancer. what can i do to prevent it?

Sun protection: Use sun protection regularly (sun block and coverings). Have any skin lesions checked out asap, and keep any routine screening appointments as recommended by your dermatologist.

Sunblock: The biggest prevention is avoiding the sun at the peak hours when the sun is strongest between 10am to 3-4 pm. Purchase a good daily facial lotion that has at least SPF 30 for a base layer. Apply additional sunblock whenever you are out for extended periods and reapply often. Retin-a applied nightly can have beneficial effect. Avoid suntanning booths and get an annual full body skin exam.