have you got the new thematic sources booklet? if not, download it off ocr. it tells you what topic each source is good for. You also need to look at as much background information as you can for each topic, eg know details about the chariot races. You'll need to be able to say who wrote the source you are referring to in the exam, so learn some of the names. Otherwise, good luck.
Goodd luck! I'm learning texts for my GCSE latin at the moment Cicero mainly and I have been to Pompeii and seen it all up close which really brought latin to life more for me :) Look over vocabulary and basic grammar rules and look at the set texts so that you're familiar with them and feel prepared for the exam. x