Engagement Shoot- What to wear

We are doing engagement photos on 7-22! Yay!I have put them off for a long time because I'm bascially really insecure about my figure. I have had some medicial issues in the past few years and I've gained a significant (read: A ton) of weight. I don't feel like my old self and I feel like i have to apologize for my weight (especially like when i went to get my dress fitted and the seamstress commented on how much thinner my face was in my license photo)...
ya that was from 9 years ago, thanks!

Anyway- I am concerned about what to wear.
We decided to do a kind of "travel" themed shoot, in our "backyard" which is absically the blackstone river bike path. There is also a really cute little museum that's in there and its a little white cottage thing- so I figured we could do some really fun photos.
There are train tracks in front of my apartment.

Since its summer I was thinking of wearing a cute dess with a swing coat to kind of "hide" my imperfections. But I am STUCK on shoes. I want to have a vintage feel and I don't know what kind of shoes to wear.

Also,I was hoping to come up with another outfit that was kind of trendy for some photos- and I'm coming to a loss! I did get an AMAZING maxi dress but i am wearing it to my bachelorette the next weekend, not that that really matters.
Help