Do not use a mix of several fonts and sizes in the same article
Choose good fonts. I wonder why is so trendy nowadays to use the thinnest font available and put it in an low contrast gray tone. It puts a innecessary strain in the eye of your public
Cheap fonts have a badly designed character spacing. The same problem happens here. Some letters look more closer than other and this is plain wrong in typography. All characters must create an uniform word and all words must have clear boundaries.
Fix your line spacing. Needs more height here for the same reason.
Plan your design and take care of the flow of your text. Do not randomly displace the beginning of some paragraphs over the other paragraphs without a good reason. Split your page using some strong vertical lines. Not a vertical zigzag pattern.