The problem you have is you created additional paragraph opening tags, let's say i have this paragraph:
<p>i am a paragraph</p>
and now i want to change the font-size, we could use the style attribute. The important word here is attribute, a attribute is something you can add, in this case to a paragraph opening tag:
<p style="font-size: 14px">i am a paragraph</p>
see? I added the style attribute to the paragraph opening tag, no need to create an additional opening tag.