Naturally, you have had the opportunity to train your reading skills all year long using the materials in Wasp Reporter.
Using the links below, you can find lots and lots of extra practice material. You don't have to do every single exercise there; just practice as much as makes you feel comfortable and confident.
I do recommend having a look at the Anglia materials; these feature a convenient overview of the grammatical items you need to understand at a certain level and will serve as the basis for your test.