Forced to buy subscription

It sounds like someone else had your console set as their Home console and you were playing their games. If they removed your console as your Home, you would no longer have access to those games. Otherwise, the only way to play games is if you purchase them or you have a subscription to Game Pass. Or Gold if you're trying to play them online or Games with Gold games.

So , I have played free for since I got my XBOX, then I got a message one day for an update or something and won't let me.play any games without getting a subscription. I never had a subscription before all games are free to play and were free downloads.

Do I need to reset my console? If I do would I have to re-download all The games I currently have?

It happened for any game. I was able to play them before, then wasn't games like Fortnite that are free to play online.

Depends

If it is an online only game like that isn't on the100 f2p list https://www.xbox.com/en-CA/games/free-to-play

Then yes like every single other console including sony and Nintendo it is a paid subscription unless its f2p

Offline games can be played without but not the multiplayer aspect just like every other console

Only Nintendo is cheaper and sony charges a lot more

did you purchase the console new or pre owned, if pre owned then the previous user left it set as the home console and has probably just got a new xbox or signed in elsewhere and set as home.