Okay so I never had a “real” lucid dream where I could control and stuff but yesterday while I was trying to induce FILD I got scared. I thought to myself, what if I become lucid and I walk out my room, there is going to be a ghost? I thought that because I know that if I become lucid I will try SO hard not to think of scary stuff but I will, eventually. So my question is: would I see scary stuff if I imagine it even for like 3 seconds? MY mind is VERY weird (like f***ed up) and I imagine all these weird stuff and I’m scared that I will really see it once I become lucid.
Maybe. But you’d also be able to imagine ways to deal with them, right? Think up your favorite weapon, or a way to escape unscathed, or an ally/guide, or even re-imagine the threat itself so now something completely ruins the scary part.
You’re human – it’s normal. 
I still hate standing in murky water in a lucid dream, because you never know what’s down there… 
One of the earliest lucid dreams I had was a nightmare where I realized I was dreaming and took control of the situation. Anyway, just be a bad*** if things start to go sour – and demanding a gift from the nasties is a good trick too.
you guys are so nice.
the feeling of fear comes from things like uncertainty, but if you see the things which you imagine in a LD, then you know what feelings inspired those monsters to appear and they will submit to their creator… you.
Ah, the "what if"s. People often forget they’re in control of their dreams, even while they are lucid.
First thing, why would such a thing appear just because you became lucid? It’s a very good thing to be conscious of your actions, so if anything, the dream should veer towards something more positive, like it does for most people who become lucid.
Secondly, do you think like you wouldn’t be able to handle that with your new awareness? Remember that you are the dreamer, and as such, you’re the only one with powers in there; so, if there’s something that is limiting you somewhat, it can only be you, your own fears. So why don’t you go and face them? Once they’re out of the way, you should be good to go 
Even better, fears in dreams often take a solid for, so they’re extra easy to address and, literally, face, in order to listen to them understand them, and in doing this, curing them.
Good luck with your LD’s! 
Typically for me, when I look for something or expect to find something in a LD I usually find it in a couple of seconds. Its a great passive control technique. If you think of something you don’t want to find, I would suggest either not expecting to find it or expect to see something else outside of your room.