Help with identifying the right type of model to use

I have a set of images, but I am not working on a classification problem like most tensorflow tutorials have. Rather, I am trying to have the model recognize/develop its own features without a validation set to label and categorize.

I don’t actually know what this type of model is called, so I am having a hard time finding tutorials.

My goal is to have a model that recognizes similarities in new photos and can select them them if they cross a threshold of similarity