When creating a post, there is not an option to designate tags for that post. There is still a checkbox for displaying tags under "Screen Options," and when checked, it still does not display. It is possible to add tags after the post has been created with "quick-edit," where an input field shows up where you can add/edit tags.
What files should I be looking in to get to the bottom of the problem? Is there possibly something I could be missing? I know there is relatively little background information in this question, but any help would be appreciated.
in the top right corner of the post edit page, under your log-in name is a tab that says Screen Options.
Click on it and make sure that the box next to the word Tags is checked. That will display the tags option in the right sidebar of the edit page below the Categories options.