Hello,

First of all thanks for choosing our Theme, we are glad to be you in the WoodMart WordPress family :-).

You can set the main product image size from Theme Settings >> Product Page.

Screenshot for Clarification: https://ibb.co/hdLmnV1

Unfortunately, we are unable to recommend any plugin for image optimization, because we haven’t tested our theme with such a plugin yet.

You can try adding any plugin that better meet your requirements.

Best Regards.