Japanese is kinda complicated with 3 different types of writing, but how do I tell when a word "ends", for example, in English, words are seperated by spaces, but those don't exist in Japanese (as far as I know at least), and for chinese, each individual letter is a word on it's own (which I assume can apply for kanji), but how do I tell when a group of characters are supposed to form a word?
sorry, I don't know that much Japanese yet so I can't really provide an example on confusing sentences or anything 😞
You're right, telling where words end is tricky at first. All I can say is it gets easier as your vocabulary develops and you become more used to the various endings words can have – for example, a two-kanji compound can be a standalone noun, or the second one may be a verb stem followed by a て, a り, a る... Prepositions/conjunctions help too - keep an eye out for は, で, に, が... Admittedly, they can be misleading too when you haven't yet learned the word that comes before. The only thing you can do is keep reading, trust that it WILL get easier, and get used to reading whole chunks of characters at a time rather than kana by kana or kanji by kanji. Also, texts for beginners often have spaces between words – for example, keep an eye on Renshuu's Discord book club.
Fortunately, it's not quite that hard. But the reason you can read the above is due to familiarity with all the words in there. As むじな noted, though, due to the interspersing of kana-only particles among mostly kanji terms, you see visual breaks in the sentence. So it may look a bit more like this
howDOyouknowWHENeachwordENDS?
(pretend that lowercase is kanji, uppercase is kana)
But in the end, it's just a lot of "muscle" memory - you have seen 今日 (for example) so many times that when you see those two characters, they kinda separate themselves from everything around them.
