Many non profits would welcome social media volunteering, as long as you have some skill . Maybe read up on what is involved in social media roles/self train--lots online then offer short term/pt skills to a nonprofit for experience?

https://hootsuite.com/podium

10 Excellent Free Online Courses In Social Media Marketing

Free Social Media Tutorials at GCFLearnFree

self training online is such a great thing. I'm trying to learn Swift/ios programming on my own--lots out there!!