BLOG Page Customization

Hello,
I need help fixing the blog page on this website: http://tintedadvertisinggraphics.com/
This website theme was created and customized by someone who is no longer reachable. I am in charge of “maintaining” the site until they ever decide to hire an actual developer. Since this is a customized theme I have no Idea how to make a blog page work. The blog page is here: http://tintedadvertisinggraphics.com/tag-blog/ I tried experimenting with creating a blog page template myself and as you can see it’s not very practical. I am not able to fix how the test post excerpt looks visually or layout wise and even when I do click on the “Test 1” post it goes to another “blog page” that I didn’t even know existed and is sort of blank until you scroll all the way down and you see “Archives February 2015” and you click on that and it shows you the actual post. I even tried downloading plugins that claim to “get posts” to any page but they seemed to have no effect.

Please help me fix all this. If there’s a simpler way of not dealing with the page templates the person created, at all, that would be great. Or if there’s a plugin that creates a blog page/posts it would be great also.