Gallery and Images

In a nutshell, I don’t have a clear idea how this is used. Every time I try to use it, I get a page with an image much larger than the original uploaded images and it looks awful.

I am going to explain what I want to do, and perhaps someone can provide me guidance.

I would like to post media in a post. I would like that media uploaded to automatically update itself on a gallery page using WordPress native functionality, IF THAT is possible.

I would like it to display in a simple thumbnail view grid, that perhaps works on a pager and loads as a person scrolls.

I would like to add taxonomy to images so in theory, these galleries can be sorted by sub-type.

So how does one do this?

A page with the [gallery] shortcode does automatically add pictures that are uploaded using the “image” format type.

My ideal theme called “Untitled” by Automattic does not have Gallery as a format type.

I tried to use Twenty Thirteen, but it is so far away from the design I need (Like Untitled) that it has become a bear to modify.

I need someone to walk me though the standard way to create these things, and tell me what I am doing wrong. The images sizes take up the entirety of the screen, and I do not have control of the thumbnail output.

I would also be very happy to use a Gallery plugin if it provides more functionality and a bonus is to auto add new content from any post format. (or specified).

I started with WordPress long before post formats were available and I am afraid I have fallen behind in understanding how to use them.

PS: I need instruction on how to use featured images without it showing up as both a full size and thumbnail image in the post too, as well as how resizing when uploading works.