It should not come as a surprise to you, when I state this fact by Cisco:
"By 2018, more than 75% of the web content will be video"
So, if you want to increase traffic to your blog then you must advertise/promote it on social media
. But this promotion shouldn't be in the form of text or images. Use videos for the promotion.
Also I would suggest you to include videos in your blog
regularly. This will boost your customer engagement process. Including videos in your blog also helps in SEO and indexing.
I would recommend you have a look at Rocketium, an online tool, to create videos. They have some discounts for non-profits.
Paid campaigns are also a nice way to get traffic, but I would suggest you to jump into these only when you have dedicated landing pages for your ads, have decided a segment you would want to target (geo location, keyword research) and have enough funds to continue the ads for at least a month.
Hope this helps!