PsychoPy can be found on the webpage https://www.psychopy.org/ We recommend installing the "Standalone PsychoPy" version (for Mac or Windows).
There are many resources on PsychoPy on YouTube - check https://workshops.psychopy.org/teaching/index.html for some links.
In the class I mentioned the Stroop demo. You can check it, but there is also a newer tutorial using more current version, which could be more straightforward to follow (Posner task).
For the next class:
1) Download and install PsychoPy
2) Watch the Posner tutorial (17 mins, ) and try to follow it on your own computer.
3) Close the tutorial, create a new directory and try to re-create Posner experiment in PsychoPy by yourself.
Posner task:
Stroop task: