If you'd like to increase the font size on Safari web pages see this link that comes from Jim Hamm. He tells us, "I set the font size to 18 in tip #one. Definitely makes web pages easier to read, although the article states this may not work on all websites. I haven't tried tip #two yet, but may try it later on."
Or, try doing Command and + once, twice, or more to enlarge the Safari page. If the site you're looking at has the Reader listed at the top click to delete the ads and bring up only the article. Then if you want it larger click on Command and + to bring it larger to read and/or print it from there.