的【de】

的 marks the owner. It goes between the owner and the thing owned, in that order.

The order is fixed and matches English "'s" rather than "of". Shū书de的wǒ我 is not a thing.

There are no possessive pronouns

"My", "your" and "his" are 我的, 你的, 他的 – the ordinary pronoun plus 的, with nothing new to learn.

的 with no noun after it

Drop the noun when it is obvious and 的 stands alone, meaning "mine", "yours", "the teacher's".

Where 的 drops

Family, and a handful of close relationships, leave it out: 我妈妈, 你哥哥, 他朋友. Keeping it is not wrong, but the shorter form is what people say.

It drops for an organisation you belong to as well: 我们学校, 我们公司, 我家.

With anything else, 的 stays. wǒ我Shū书 is wrong; it has to be 我的书.