Have a listen to this crashcourse: Typography Tutorial - 10 rules to help you rule type - YouTube
Of course these rules can be broken but they’re a good starting point, especially if you’re having issues.
Pick a good font and possibly a good secondary font (like a nice sans-serif for titles and a serif for body text) and stick to it. Don’t mix up all kinds of typographic elements, use a few sizes, setup a simple grid and you should be ok.
I have been using DIN everywhere for years. A nice bonus is that I can mix and match content I’ve produced into a website/portfolio and things don’t clash.