Basics first, please get rid of any plastic furniture like that chair. secondly all table tops need to be cleared of little mirrors, table clocks etc. just place three most loved items of your choice ! Arrangement can also be improved the table could come on the side and bed could be centred a bit better (along the window behind it). Walls can be painted a neutral shade like light beige with a rug of your choice on the floor (contrasting- like red so that the pink curtains could go with it)If you could change the curtains then the best option would be to pick a solid colour of your choice and a matching rug (blue, red etc whichever is your fav colour but please avoid printed cutrains)

help me regarding the design of my furniture (bed and headboard,cupboards and dressing table which sheet should i use for it , and suggest me which colour should i paint to my walls , presently i dont like the paint of my walls , how should i paint ,should i paint four walls same color or should i use different colors for the walls

How about a picture of the room and furniture that will be in it? Otherwise, any suggestion is totally meaningless.

Could you post a few photos of your room? It will help us help you.