How to tan healthily? without getting cancer and skin damages

There isn't: Tanning is your skin's response to damage from uv rays. Your skin is trying to protect itself. There is no such thing as "safe tanning". If you spend lots of time outdoors, where sunblock, reapply often, where a hat if you can. Tanning less now will reduce the effects of sun damage later including wrinkles.

Sunscreen : Sunscreen will not stop all if the ultraviolet radiation from reaching into the skin. The uvr that gets through will lead to tanning and sometimes burning . Remember there is no such thing as a safe tan. Tanning greatly increases your chances of developing skin cancer.