The Advent of Code is a free, yearly event that spans over the month of December and is organized by Eric Wastl and others. It's basically an advent calendar with small, daily programming puzzles that can be solved in pretty much any language and should be fun, independent of your skill level. Further information can be found on their website adventofcode.com.
This is my first year participating. I'm most comfortable with Python, however about a year ago I started casually learning C++ - I'm not a professional programmer -, and that's also what I'll primarily try to use for the challenges. I might do some in Python though.
I'll upload the challenges at least a day after they actually happened to respect the organizers' wish to not post on the same day and thus spoil the fun for others.
If you'd like to try the code yourself, you can check the top of the relevant main.cpp file, where I describe how you can compile and/or run the code at least on *nix systems (eg. macOS, Linux) in a terminal.