This is a backyard wedding so no one needs to be wearing a full gown or a tux. Just look your best in semi formal attire like a suit or a dress. Since you'll likely be on grass or uneven terrain we recommend that women wear a block or wedge if they opt for heels. October can be a bit of a gamble in terms of weather so we recommend you bring a light jacket, shawl, or warm suit jacket. Trevor you can't wear a kilt.
Both the ceremony and reception are taking place at Jay and Kate's home in Portsmouth. Depending on where you're staying you could absolutely walk to the location but if not, all the street parking in our neighborhood is free and you should have no problem finding a a space to park. If you're staying downtown I recommend taking an uber or carpooling.