“I don’t see how the Senate can have a trial on an impeachment that hasn’t happened.”
I don’t think there is a prescribed way for an impeachment to be delivered to the Senate. The fact that the House has voted for impeachment isn’t exactly a secret; the Senate can take their copy of the Congressional Record for that day to be that delivery.
I can’t think of anything the Senate takes notice of from the House without being officially informed.
Pelosi is making a mess of our Congress.