Cook it according to the directions!! If it doesn't have different timing for fan forced then give it a little less time. Cake is cooked when it springs back when lightly touched, I usually don't use a skewer as well to test but you can- just slide it in and if it comes out clean its cooked.

Good luck hun!! If I was closer I would come and help I love making cakes.

ETA If you want a really easy fool proof vanilla cake recipe I can give you one.