Let me guess, you were using pirated versions of Office on Windows, lol. No judgments here. You can get cheap versions at Shopee for few bugs, they will work on both PC and Macs, up to 5 computers. Only thing you have to remember not to sync any documents with Cloud Sync as the sellers might have access to them.

You can buy Office annual memberships, but they are costly. Offline versions cost at least 5 or 600 bucks per computer, so shopee might be the better choice.