i learnt that u must never separate syllables in english :0 !!

i remember asking a teacher about it when i was like 12 and he just told me syllabic separation wasn’t important. which does make me wonder – when one is writing on paper and runs out of space at the end of the line, what does one do? does one just write the entire word in a new line and leave the end of the previous line empty? this feels wrong and wasteful. maybe it’s just one of those things only native speakers have to worry about and us don’t