Not knowing what/where you want to apply this new knowledge, I'd recommend learning Python. It's a very good beginning language and it can be applied to many different areas (web, science, research, etc...). You can also easily apply the general programming knowledge you learn in Python to many different languages.

Some free Python resources: - Dive into Python - http://www.diveintopython.net/toc/index.html - Dive into Python (v3) - http://getpython3.com/diveintopython3/whats-new.html - Official Python Tutorial - https://docs.python.org/2/tutorial/index.html - Learn Python the Hard Way - http://learnpythonthehardway.org/book/ - The New Boston Python (videos) - https://thenewboston.com/videos.php?cat=36

HTH