well “着”usually don’t have a specific meaning，u can add it to almost all of the verbs and the meaning won’t change.
examples: “听 ”and“听着”are almost the same ，both of them mean listen/hear “看 ”and“看着”are almost the same ，both of them mean look/watch/see u can say 当我在听音乐的时候，天空开始下雨。 当我在听着音乐的时候，天空开始下雨。 They’re the same 🤣
but sometimes there’ll be a little bit different examples: we say看书，but not看着书 看书means you are reading a book 看着书emphasizes the act of looking at the book It depends on accumulation and this case is very rare💦
so in general，着can be added to most verbs and actually it won’t change the meaning!
yeah you’re absolutely right! 贴贴is a fashionable way to say hug,most popular among young girls u can say贴贴to your close friend and it’s widely used it can express express your comfort or gratitude, or just a catchphrase🥰