Keep the environment you put him in clean. Only use newspapers as substrate and if there's faeces, clean it immediately. For the rest, create the right conditions (hiding places, temperature, ...). Just make sure nothing get's in the wound.
You can also clean the wound and disinfect it with something that doesn't sting. But if it's from yesterday and it looks ok, I would leave it. Maybe there are other opinions here
edit: Of course welcome to the forum!