Last night i had my first LD and i was really excited, when it started i was already thinking of the things i wanted to do but nothing happend, instead a window opened like a browser and i could select scenes and play them… and then i lost lucidity.
How do i actually do what i want i simply imagine it or do i shout it out loud?
Experiment. Use thought commands, imagine it, or speak it out loud. You’ll find a way that works for you. Some people find that it’s easier to speak them out loud, at least at first.
Thanks
Oddly i have had this browser, console, like problem. Mine was a bit different though. It sounds kind of Inception-esque. but i was in a ND which had zombies, where i was in an unfamiliar house, but with friends. and i go to sleep in this house, and tell my friends to wake me up if any zombies come in and ill “get em”. Anyways, i take a nap in this dream, and go into a completely different dream. This dream being in nearly the same house but alot brighter vibrant setting. I then become lucid in this dream. talking with my best friend IRL, helping each other practice flying. after a good ~10 min lucid dream, i am suddenly hearing “WAKE UP!!!” “WAKE UP!!!” in the background getting louder and louder, i had completely forgot that i had a dream previous to this obviously, i then slip out of this dream and oversee myself sleeping in the chair in the previous dream. but this sort of, PAUSED menu has formed, and i’m suddenly third-person. Then by the time i had realized what i had to do and pressed wake-up/continue, i got bitten on the neck. and that dream ended. weird.
On a different note, yes thinking is obfuscated in dreams, or tends to be for me atleast, i just roll along with my dream having fun with the realization im dreaming and flying or using telekinesis. which are my favorite. in my past 3 lucid dreams, i cant gather myself enough to do my personal tasks, which at the moment, are cut myself and regenerate it. and walk on the floor of the ocean with a torch 
but going with the style of dream that you are having is definitely fun and worthwhile
Try opening a terminal… or yelling it.
I start thinking that our brain is really a super software that we are not able to use …till now
To me, demanding seems like the most reliable way, even though it doesn’t always work. I guess it’s about the mindset you have while demanding.
You need to 100% sure that you will succeed, but then if you were 100% sure in something there shouldn’t be a need for demanding, right? Then things would manifest just by them selves! 
That would be awesome but I guess that should be very high lucidity to achieve something like that!
I just shout out something to the sky. It’s like talking to your dream.
When I want something I usually doubt a little if I can do it so… I just tell myself IT IS there, no doubt. So I jump off something knowing I can fly instead of trying to make wings to fly. Same with shapeshifting. I know I am a wolf, instead of working out the details. If there is too much doubt, everything gets more difficult . Hope this helps.
When I want something I demand that it happen. Usually I just think it but when im able to I shout out the demand and that seems to work better than just thinking it. I like to think of it as enforcing my will upon the dream world