First of all, non-oil based products for you! Get a good moisturiser. Foundation isn't necessary - try a high SPF moisturiser instead if you have good skin. Try maybe a foundation that's cream to put on but has a powder finish - they look great if you're not too sure. If you want powder foundation it should look pretty not-there - you need a good brush and put it all over, then do your bronzer on top of that.

Sensitive skin means that you should go really light on foundation else you'll come out all spotty, so use heavier foundation, so get worse skin... it's a vicious cycle so don't start it!