What's the difference between __をするのが好きです and 私は__が好きです? 私 means me, すき means liking/fondness, and です is a polite copula. I know that much; but, I haven't been able to figure out the rest (mainly the difference between の and が, how does を work, and what does する mean in the first sentence).

How can I know when is it appropriate to use お before a word, like putting お before 寿司? I've seen that putting お before 寿司 and 茶 makes it sound better, like more respectfully. When is it okay to use it? Haven't been able to find much on the matter.

How can I know when is it appropriate to use お before a word, like putting お before 寿司? I've seen that putting お before 寿司 and 茶 makes it sound better, like more respectfully. When is it okay to use it? Haven't been able to find much on the matter.

Could いってきます be used as a form of "brb"? I've read that いってきます literally means "I'm leaving but will be back," so I'm curious to know if it could be used as the Japanese equivalent of "brb." I know it's normally used when leaving someone's house, but I'm just wondering about the possibility of it having another use based on its literal meaning.