Ohay and welcome.
Since you're already in Billericay, it'll make things easier for you, as there are two good sites there.
Someone further above mentioned "Tower Minis", which is a fortnightly Tuesday evening game at "The Tower". This site is run by the folks from "Airsoft Plantation", which is another site pretty much just around the corner. AP runs Sundays, while TT runs Saturdays and the aforementioned Minis every two weeks Tuesdays, so plenty of chances to get out and about locally to you