I think I saw somewhere that when the subject is a personal pronoun you don't need it. like, you should just write ты студент. but on here I've seen people adding it when correcting notebook entries so I'm kind of confused as to whether it should be there or not...

Hi! You need not pronounce it at all.It`s the sign,not the word.It means the absence of the predicite which in european languages is expressed with the help of "to be". For exm:"you are a student" in Russian is written with - instead of "are".It is a dash.And it`s read and pronounced as "you a student". Irina wrote some examples with a hyphen but there are more of them. The sign is used to separate the syllables in written form.It`s better not to mix a hyphen, a minus sign and a dash.The "minus sign" is used only in the connection with mathematics.

1) to contract words. eg гос-о (государство) - you must reand the full form of the word

2) to add necessary suffix почему-то - you must read just like "почемуто"

3) in some words with 2 roots тёмно-синий - to read "тёмносиний"