Most of the time you see spelling that's weird in English, it's because it used to be pronounced that way and now it's not. Same with German.
Unlike
>>13788082, we don't reform our spelling so it reflects how we pronounced it hundreds of years ago, rather than today (which varies by dialect).
And some spellings are spelled on a false basis, that is, they were never pronounced that way, like: 'scissors', 'island', 'ache', 'could', and 'sovereign'.
Though to be fair, German has had a few recent spelling reforms.
>>13788118Again, historical spelling. The h used to be pronounced, now it's not. But it's still useful for ch and sh.
As for "ll", it represented a sound that's still around in a few dialects but has disappeared in most: the voiced palatal lateral approximant.
As for J representing /x/, I'm not sure the whole history behind it but it's also due to sound changes.
Speaking of, you have historical spelling as well: "Ł", pronounced /w/ (voiced labial–velar approximant), used to be pronounced /ɫ/ to distinguish it from /l/; two different L-sounds. Hence, why it uses the letter L with a stroke.
