Every spray tanning application or self tan lotion application requires some time for the bronzing reaction to take effect on your skin, so DO NOT shower for at least 6-8 hours after the application. The best thing to do is to have it in the afternoon and let it react overnight.
Only use a moisturizing lotion after you have your shower and then moisturize every day thereafter. You will see some of the color wash off in the shower after your first shower but you need not worry, this is the bronzer which has now reacted with your skin to change its color.
Use common sense, you have had a product sprayed or applied to your skin that needs time to take effect, so basically plan a night home with a DVD or get an early night.
Your tan will last and you will be looking fabulous.