Want some programming exercises? http://adventofcode.com/
is an advent calendar of relatively easy challenges. Every day so far had a straightforward solution and then a surprise twist that required re-thinking the solution.
You are on a Chromebook, you say? Then try https://repl.it/
Also, if you feel the need to have a Linux console, Google Cloud Shell (https://cloud.google.com/shell/docs/quickstart
) gives you one for free. The setup is a little quirky with the need to setup a project, but it's described on the quickstart page how you do it. Note that Cloud Shells do have some local storage but are garbage collected after one hour of inactivity. The shell in the browser allows you to receive and send files, though.