Going to Mexico

I had a squamous cell cancer removed from my upper lip 1 year ago. I had a Moh's procedure done- it was kinda scarey- but the area was very tiny. Anyway, I am going to a resort in Mexico with a friend who worships the sun. She keeps telling me I should get a "base" tan before we go, so I won't burn. This sounds contraindicatory to me. I was going to get spray tanned prior to going and use SPF 45 while I'm on the beach, try to stay under the umbrella, etc. But I don't know what else to do- I should not have booked this vacation, but $2000.00 later I'm going- any suggestions???????