https://www.lynchburg.edu/academics/writing-center/wilmer-writing-center-online-writing-lab/grammar/a-quick-guide-to-punctuation/

https://libguides.reading.ac.uk/writing/punctuation

https://www.butte.edu/cas/tipsheets/practice_punctuation.html (detailed, advanced)

https://www.learngrammar.net/practice/35/exercises-on-punctuation (a short quiz)

Just for fun :-)

https://www.youtube.com/watch?v=zVu-XvULZNg