Why is my enforcement action a year ban and how do I reset the strikes?

If they denied it, then all you can do is wait it out.

I did and they denied it instantly, this the last thing I haven’t did

The enforcement team does not use the forums. You would have to check the enforcement site to see about submitting a case review. https://support.xbox.com/en-US/help/family-online-safety/enforcement/how-to-submit-a-case-review

So if i got a enforcement in the future and i explain my situation the chances of getting gamerscore reset are very slow right?

And why people got gamerscore reset years ago and some got permanent ban, they dont do that anymore??

Im sorry if im very annoying about these, im having a lot of anxiety because of this, so im asking because i need answers to be calm

Not really low. If you get an enforcement in the future then someone would have reported your account. Depending on the enforcement team's investigation, they can issue a suspension for whatever was reported and also do a reset or ban.

The people who are being banned and say they had a gamerscore reset years ago could be mistaken on why they were banned and may actually have had multiple other enforcement actions or did something else that would warrant a ban. Most people post that they did nothing wrong when that's not true.

Support are nothing to with enforcement so can't help or do anything.

You say you haven't used the account for years so it could of been banned before the enforcement site was around which is why there is no info.

Any enforcement action has to be appealed within a year so if it was banned years ago then there's nothing that can be done.