Word of advice; be paitent. Majority of the times Artists mess up when they have had enough and just want the picture to be done and published to the public.
Be paitent with it

and if you do you know it is not the best picture, at least you can say you tried your hardest.
The background, there is many parts of the backgroud I like. But there was some parts I didn't like around the 3 bodies.
Maybe the lack of detail like coloured rocks was due to you being so impaitent, when those things are coloured like the rocks, it looks so much more professional(especially the feet

)
The smoke was probably the first try. Don't worry you will soon get the hang of it no doubt
Just keep practicing and soon you can be on par with many big artists
