I would increase your font-size of both your paragraphs and headings to make the text more readable. You might want to increase the weight of the headings as well.
Also you should aim at lowering the amount of characters per line. Currently on desktop your lines are about 109char/line on your about page, which makes it difficult to read. That should be brought down to around 50-70char/line. You could do this by reducing the parent width or by using columns.
Take a look at this source for ideas on fonts and font pairing:
Lastly, if you are interested in web typography I’d really recommend Jason Santa Maria’s “On Web Typography”(http://abookapart.com/products/on-web-typography).