I don't think Trump performed badly, but he woefully underprepared. She oozed politician sleaze, and held her own. It was a minor win for Harris, but I don't think anyone was particularly impressed.
She has a brand new vibey persona, and completely different policy positions to everything she's said in the past. If Trump want's to turn it around, he's gonna need to redirect the debate away from abortion, and back to the economy, foreign policy and immigration. Attack her record, and her phony politician persona. If he manages to convince people she's responsible for Bidenomics she's finished
I highly doubt we'll see another debate, so it will probably be an information / propaganda campaign going forward.