there is a wealth of resources for learning mandarin but only a smattering for cantonese.
two favorites:
1. web dictionary http://www.cantonese.sheik.co.uk/scripts/wordsearch.php?leve...
2. iOS dictionary that is free and comprehensive, also covers mandarin: https://apps.apple.com/us/app/pleco-chinese-dictionary/id341...
unaffiliated with either company, just a longtime user.
other suggestions for cantonese resources welcome.
I've found it surprisingly hard to find a summary of the differences.
By contrast learning German from Danish seemed to have some bits that made it clear reasonably fast.
And can't you just start watching TV shows and movies in Mandarin? It should be a lot easier than for us mortals who start out without knowing any Sinitic languages. We have to work hard just to handle the tones and the near total lack of shared vocabulary.
I am puzzled that learning Mandarin for you hasn't gone much the same way as learning German did.
There is of course the standard way of playing with HelloChinese (or similar apps) and LingQ/Du Chinese (or similar apps) + reading easy readers (Mandarin Companion, Chinese Breeze, and similar). You should be able to speedrun them, compared to the long slog path that we mortals have to take.
(A fellow Dane with zero East Asian parentage.)
Cantonese and Mandarin weirdly seem to have wandered further from each other than Danish and German. At least for me, but that may also be lack of exposure.
unfortunately, i failed to cherish this opportunity and spoke english predominantly as a child, leaving me with heavily-accented and vocabulary-limited cantonese.
i have spent an inordinate amount of time repairing these deficiencies and learning mandarin as well.
a little more self-awareness and foresight as a teenager could have saved me years of learning as an adult.
on the upside, self-learning has yielded insights into chinese language and culture, learning, and accents. unsure if these other perspectives are worth the extra time and effort, though. :)
* jyutpin typing game https://chaaklau.github.io/cantorocks/