Gallery Plugin help

I have done a search but the task of wading through all of them is daunting so I dare ask it here.

I am looking for a plugin that will display thumbnails in a post that are clickable to enlarge in a new window. I am looking for something basic such as a plugin as I don’t know much about coding. I already have a gallery outside of WP (www.markbillings.us/imagegallery) so that’s not what I am looking for.

Thanks and sorry for adding yet post to the plethera of “gallery plugins” inquiries