Frequently (daily, or a couple times per day)
- reddit/imgur (news, jokes, tech stuff, etc)
- instagram (for the pics... though slowly losing interest due to the ads)
- twitter (news, fake-news, and tech stuff)
- HN (news)
- telegram (various programming channels)
Regularly (once or twice a week)
- linkedin
- ello
Infrequently (once every week or two or three or...)
- facebook (I hate it, but all my friends/family are there)
- google+ (photography groups)
- vimeo
Practically never (once a year... maybe)
- pinterest
- flickr (really just to remind myself it's still there)
- tumblr
Python is a great start. Pick up a simple front-end framework like bootstrap. Get good at using the two to build simple websites for yourself (just make something up like a fake restaurant website or store inventory website). Then start looking at web frameworks related to Python. After all that take a look at PHP and PHP frameworks and try to learn at least one really well (eg. Zend, CodeIgnitor, Laravel). By that point (a year or two from now) you'll know enough about the web development industry to carve your own path through the forest.
Regularly (once or twice a week) - linkedin - ello
Infrequently (once every week or two or three or...) - facebook (I hate it, but all my friends/family are there) - google+ (photography groups) - vimeo
Practically never (once a year... maybe) - pinterest - flickr (really just to remind myself it's still there) - tumblr