I know I’m not dreaming simply from the fact I can even ask if I am dreaming. When I’m actually dreaming the most random stuff can happen and I don’t even question the fact that it must be real
I think the idea is to form a habit or a tick that is so strong it carries over to your dream. So like, if you commit to wearing a watch everyday, and check it every 5 minutes, eventually you'll do it in your dreams too. Then, you don't have to intentionally check whether you're in a dream, hoprfully you'll just catch the time being wildly different and be like "holy crap this was a dream??"
Yes, that is correct. It's one of the strategies you learn when you start diving in to lucid dreaming. Another is to look at some writing (maybe even this sign) and look away and look back, it will say something else if it's a dream.
I got really into lucid dreaming when I was younger, but I couldn't fly because I guess I just have no imagination, so I gave up.