How to Winterize a Camper

Hi guys 👋🏼 I'm about one year deep into living up here in San Antonio and don't really know where else to go. In the past, this subreddit has not let me down. I'm located in the Live Oak area and my parents have a camper in storage over in Converse. Unfortunately, my dad passed away back in August and I was wondering if someone wouldn't mind helping me out with a how to? I know I can Google/YouTube it but I really don't want to get out there and be SOL. Anyone wanna volunteer as tribute or in the area that can help? I would very much appreciate it. Thanks!