images sizes – aspect ratio

hi folks, i’m so confused about image sizes and aspect ratio. thanks for helping.

i’m setting up my woocommerce shop and want to go out to get images, then have them in the right size to look right. i’m using this theme http://themes.kubasto.com/everything. i’ve found the woocommerce product display settings here http://www.awesomescreenshot.com/image/127901/b78a063a4a08fb3f2441b74864262679.

problem. my images are all different sizes and using the settings above, they are displaying on the product page as

1. main product image = 468 x 468. my original actual image is 1200×1200.
2. the thumbnails below the product image, is displaying as 143×143, my original image is 1200×1200.

on the demo theme, the author’s images are displaying as

1. main product image = 468×624 (actual is 600×800) aspect ratio is 3:4
2. thumbnail under the main product image = 143×190 (actual is 364×468) aspect ratio is 7:9 -see http://themes.kubasto.com/everything/shop/ashley-short-dress/.

question. what sizes do my images have to be to all look uniform like the demo? or is there a way to auto change/set the aspect ratio of my images to work on these pages without distorting the images?….perhaps by adding white padding around the image?

thank you!!!!

https://wordpress.org/plugins/woocommerce/