Guild Wars 2

Hi all,
i am kind of a new player and i need help regarding the game updates, is there any kind of a site that shows incoming game updates ?
and also i really wish to see the changes that happened to the classes in the game.

thanks in advance.

Complete information is not available until soon before the update (usually just an hour or two) on the Game Release Notes part of these forums : https://forum-en.gw2archive.eu/forum/info/updates

They also tend to add (nowadays) a little preview video on their main-page a week before the update (so basically each Tuesday where they are not an update).

https://www.guildwars2.com/en/news/
And for the specific release coming on Tuesday: https://www.guildwars2.com/en/news/prepare-for-the-escape-from-lions-arch/

And for historical releases (this usually gets updated soon after the patch goes live): https://www.guildwars2.com/en/the-game/releases/

The exact time for an update is never announced. This to avoid people logging in at the exact right time and crashing the system. Most content updates are on tuesdays, once every two weeks. The next one is expected the next tuesday. Mostly they are round 6pm UTC

Only at that moment the release notes are published.
Hotfixes are never announced and happen at random. They do not take the servers offline to update the game. Players online get a message that a new update is available. You can decide for yourself to log out to start updating, or you will be forced when you decide to change map (loading screen) or after a certain amount of time has finished (regular maps 1 hour, instances like dungeons I think is 5 hours).

lordkrall has linked to the info bout the next big update.

As for class updates. Those updates are put up for comment by the community in the profession balance subforum. Currently in this thread: https://forum-en.gw2archive.eu/forum/professions/balance/Feature-Build-Balance-Preview/first#post3568077

Also other things are often announced (e.g. the announcement of removing Glory from PvP as a currency). Some good places to keep watching those are www.guildwars2.com or wiki.guildwars2.com