We did it last year...
I was a little worried as I am not a churchy person but I loved it and will definitely go again.
We went with friends 4 adults 3 children and were all seated together round a large table. Food was fabulous and you could keep going back. The kids loved that idea and tried new thinks.
The music was brilliant...even though I am quite a reserved person you end up clapping your hands sat down and then standing up.
If you don't want to join in you can simply sit, there is no pressure at all.
The one thing I would say is dress correctly.....For many this is a church service, the local people are dressed nicely so I wouldn't go in beach type gear.
In saying that you don't have to go too neat....both the men with us wore shirts and I wore three quarter trousers and a pretty top. The children were in normal smartish shorts and tee shirts.
Have a lovely time. This is one not to miss.