No, I'm not saying that. Making fanfiction or roleplays is not going to help turn your ideas into movies. It's already been established that turning them into movies is pretty near impossible.
What I am saying is you can still "bring your ideas to life" so-to-speak through fanfiction or roleplaying. You can either write fanfiction and let fans read them or you can start a roleplay and everyone who is interested can participate in your ideas and add some of their own.
But writing fanfiction, roleplays, making comics, etc, none of that is going to help you turn your ideas into movies because Universal is likely not going to consider your ieas even if you sent them to them. That's just how things operate in the real world. It's not that easy to get your ideas made. Countless ideas are rejected all the time, from what I understand.