Alrightey well I'm kinda new to the whole liquid foundation scene, so I just wanted to know how to apply it so it looks natural and stays on as long as possible. I bought this foundation: http://www.beccacosmetics.com/COMPLEXION-Foundations-&-Concealers/c3_10/p14/Luminous-Skin-Colour/product_info.html

And this powder:
http://www.beccacosmetics.com/COMPLEXION-Powder/c3_13/p18/Fine-Pressed-Powder/product_info.html

When applied by the lady at the counter, she used a primer and concealer but I couldn't afford to buy all 4 so I just got the powder and foundation. Will this still give a good effect?? How long will it last without a primer and will my blemishes be obvious without the concealer? I have fairly oily skin. I want to use this tomorrow and I have two different foundation sponges which I want to use. If I use a sponge, what do I do with the foundation to apply evenly and naturally? And is not using a sponge better, like using your fingers in the way you apply moisturiser! Help!
I need answers to be very detailed and preferabbly step by step. So after I apply the foundation, do I apply the powder? But won't the foundation rub off when I put the powder on? SOOOO confused!