Which model? You can install Windows or Linux to most Chromebooks but the process varies slightly from model to model. You could try following a YouTube tutorial. You'll probably have to disable the write protect which appears to be as simple as removing a screw from part of the board.
There's a subreddit for it here:
https://www.reddit.com/r/chrultrabook/
You might be able to find a guide specifically for your computer by using Reddit's search function.
If you have exceptionally weak hardware you may not be able to play TLOPO anyway so I would compare the model's specs with the recommended & minimum specs on the TLOPO website. Regardless, Windows and Linux are both more powerful for most tasks over Chrome OS, so you'd be better off ditching Chrome OS anyway.
If you aren't comfortable or strong in using the command line, or willing to get comfortable with it, I would stay away from Linux. It'll never be as user friendly as Windows.
If you don't own Windows, you will have to either buy it or pirate it. I would never blanket recommend pirating Windows, because if you happened to not be careful enough, you could end up with an infected OS. However, I use LTSC for its lack of bloat, which is only officially available to enterprise licensees. You might be perfectly fine with Home or Pro.