Here is a range of resources to support with vectors (it goes above the level you need): https://www.khanacademy.org/math/linear-algebra/vectors_and_spaces. The site/app is worth an explore.
Being able to add and resolve vectors is one of the key maths skills you need to access most of the G492 paper. All of the maths is GCSE level but you need to be able to use it without thinking.
Here are some resources to support:
In you G492 exam there will be a section C (this was missing from your mock). The questions are based on a pre released article: http://www.ocr.org.uk/Images/165500-unit-g492-advance-notice-june-2014.pdf. We will go through this in class and we are quite good at guessing what will come up. It is worth having a look through the article and start having a think about what you will need to work on.