Is this ok for a wedding? And what do I wear with it?

[TwoBlueFish]

April wedding but not in this country (should be about 20 degrees) and is at a vineyard. I really like it (it has pockets!) but I have no idea what to accessorise it with. I can’t wear heels unless they are blocky and I have wide feet. I’m usually a T-shirt and jeans person but am trying to go outside my comfort zone as I’m very nearly 50 and need a change.

I like it. I don't know whether it matters to you or not, but you look very youthful in it with your nice figure and long hair. It may not be the dressiest dress in the world, but I find as I get older, less is definitely more, and something fresh and simple is a lot softer than going all out which I feel ages me. Gold or silver shoes would be nice.