Always Use A Version Control System
"This is my stupid application that I just want to learn something" is not even a good excuse to not use a version control system.
A very long time ago, using a source control system (or Version Control System) required installing a server, configuring it properly, installing the client and then you could keep track of the changes you were doing on your code.
Today there are lots of options that can work in a standalone fashion: Just install the client and you're done (well, mostly done, you still need to initialize the environment, but that is mostly straightforward these days).
And, again, there is no good reason to not start a project, as simple as it will be, without a version control.
The VCS will allow you to explore new changes without breaking the main code. It will allow you to save a half-way change to make a complete different change.
And, in the long, since you'll end up with working in team and will be required to use a VCS, you'll be used to using one.