If you're new to running then don't worry there's still plenty of time for you to get in enough training for you to be ready to tackle the 13.1 miles in August. There are plenty of training schedules available online, Runners World offer a great one to help you if you are a Half Marathon beginner.
Most schedules are 10-12 weeks long so between now and May try to start getting some runs in so that you have a good base to start from. If you haven't run before or have but not for a long while try to start with walking which you can then add running segments in to gradually over time. The NHS Couch to 5k programme is a great place to start or why not try joining one of the local clubs who will be able to support and guide you through your training. Why not join a running club and go through the journey with others? You don't need to be a "good" runner to join a running club and there are many advantages to becoming a member. Joining a club is a great way to get used to running regularly. There will be experienced members that can offer advice on all aspects of running - remember everyone was a beginner once. You will also meet people with similar interests as yourself and can be a great way to socialise - the miles feel like they go by a lot faster when you have people to talk to! Why not take a look at the Clubs page of our website to see the local clubs available in Newark.