Blog issues

Hi, I haven’t been able to solve this problem yet:

And now I have a new issue regarding my blog. I got my first comment on one of my posts and next to that person’s name, it is my photo that appears. How is that happening and how can I fix that please?

And again the headings in the blog are all wrong and I have no idea how to fix them. On op of the comment box it says “One thought on (blog title)” and the text on that heading is way too big. Anyone know how I can customize my headings on blog posts?

So I figured out the font stuff, I just played around with headings.

The only thing I still need is that picture of mine appearing next to people making comments on my blog.

And, I would like my blog page to display images that people can click on to take them to the blog post, how can I do that?