Is there a list of all Speedrunning Events? There seem to some forums for these Events, but i didnt see AGDQ.Please like if you commented something, so i get a notification.

The GDQ's are primarily organised through SpeedDemosArchives.

But my main question remains, is there a list off all Speedrunning events?

Either below the normal speedrun.com forums or on the SDA forums is where 90% of marathons and events are going to be posted.

Many of them are posted here: https://forum.speeddemosarchive.com/board/community_marathons_and_meetups.html There's also a list on the right with upcoming marathons here: https://reddit.com/r/speedrun