Multiple HTML and browser versions limit choices, at least for those on limited budgets. However, many users have not upgraded. The choice is to either limit yourself to the lowest common denominator, or lose control altogether for some users. Even if different browsers support the same version of HTML, they will often display it differently. Those with very large budgets can develop individual versions of pages for each browser.
Web browsers give their users the ultimate control over fonts, colors, backgrounds, etc.
They can choose to override your choices. A personal web page is a good place to start. Your name, what you are studying, your hobbies, likes and dislikes, pets, children, jokes - all are good raw material, but don't put anything on the page that you don't want to be public. Using fonts other than the default font can be dangerous, because the same font, by name, has to be installed on the user's computer. If you are used to print, where color is very expensive, get use to the Web, where it is free.