Train
The nearest train station is Westcliff which is a 7 minute walk from the Cliffs Pavilion. An alternative line would be Southend Victoria train station which is a 23 minute walk or 7 minute drive from the venue.
Hotel
This is a beautiful boutique hotel located close to the wedding venue. It is a 13 minute walk or a 3 minute drive to the Cliffs Pavilion There are also several BnB's near the venue, and hotels further out. A quick google will show lots of options :)