Image Gallery plugin

I’m not sure if I’m posting this in the right place or even if I need to have a plugin for what I’m looking to do. I have custom post types and each new post I want to add images to it. I don’t want the images to show up in the post itself, but instead want to have a button inside my post named something like “gallery” where you can click on it and see all the images from the post gallery in a lightbox. Does anyone know if this is possible with or without a plugin?

Any help would be great.