Gallery Options

I am trying to manage my galleries, but I am in the wp-admin and only see a place to manage media.

When I click on Media, I don’t see galleries. I see certain images attached to pages, but nothing about galleries.

Goal: I want to update ALL thumbnails in a particular gallery to be 200 in height with an aspect-locked width. I don’t know how to do this. Right now, all of my images are cropped in thumbnail view (which looks pretty dumb). I want the entire image to show up in the thumb, but have a height of 200.

Ideas?

Also, I want to do this for future galleries as well… show FULL images, but in small thumbnail view. I may want to adjust the height differently in different galleries.