All gates are about 2 minutes from each other in the main terminal concourse.
Flight are called over the PA system but the best way to stay informed is via the flight boards. They count down in 5 minute intervals (E.g. FR8296"Boarding in 5 mins")
You wont get lost. Don't worry.
Sadly it seems i spend more time in Bristol airport than my office at the moment.
Smala01