if you are in a rental you can buy tension curtain rods (no holes) and use blackout thermal curtains

Thanks

They sell this window tape. It looks and feels like much thicker clear packing tape. I put it around the window edges where the glass meets the frame. Really helps. Door snakes for the bottoms. defintiely thick curtains.

Blackout thermal curtains

How can we fix these? Please don't say cling wrap; I hate that stuff.