The Theory Test must be passed before your Practical Driving Test although its ok to take driving lessons while you study for the theory section, your driving instructor will be happy to answer any questions you may have.
Find your local Theory Test Centre here on the GOV.UK website
Hazard Perception Test
Before you start the hazard perception test, you’ll be shown a video about how it works. You’ll then watch 14 video clips. Score high points for spotting the developing hazards as soon as they start to happen. The maximum you can score up to 5 points for each developing hazard.
You can practice the hazard perception test on the GOV.UK website