We'd recommend dressy casual. The ceremony will be outside and you will likely be walking through grass quite a bit, so choose your shoes wisely (maybe leave the high heels at home for this one).
If you aren't planning on driving to the venue, we'd recommend scheduling an Uber.
There is a good amount of parking at Climbing Bines, though we would still suggest carpooling if you can.
In fact, Climbing Bines opens their "grain bar" for wedding guests only before the ceremony. It's a super cool space, check it out if you can!