i have had two lucid dream now, and in both dreams i am trying to do stuff like fly, kill etc. but i am never able to do these things in my lucid dream. why is this?

first lucid dream.
i was in a building with a few people that i don't like, since it was a while ago i can't remember how i got lucid, anyways i wanted to blow their heads off so i concentrated on it happening and watch them suffer (seems pretty cruel, i dunno why) but nothing happened, everything was normal. then i tried to make a gun appear in my hand so i could do it myself, still nothing happened. i was so annoyed i woke up.
what can i do?

2nd lucid dream
i was in a little shack that was suspended above the ocean with a few mates i have not seen in years, i then realized i was lucid because one of my friends was talking about lucid dreams in my dream, it then snapped to me that this was a dream. for some reason just when i realized that i was lucid he started making really LOUD and harsh noises.The only thing i could think about was making him be quiet, so i concentrated on a calm version of him with no noise, his noises slowly began to die down but they did not disappear. i though it was good enough so i started to try and make my self fly, gravity was still doing it's thing and i did not move i could feel myself fading away from the dream and i woke up.

why is nothing working out for me in lucid dreams?