font changed on one post

Hi, I did a blog post in Word and noted that it’s a different font than the rest of my site. I guess I thought when I copied it into the blog post area it would reformat to match the font throughout the site. I can’t seem to find where to make the font style change. Can you let me know how to do that? And also, what is the font called that the theme normally uses so I can make sure to reformat it prior to copying/pasting if I ever need to do that in the future? Thanks.