Ok keeping in mind of your age, I think what you need to do is have something sophisticated while inc-operating peter-pan. I am only going to mention the basics I would say colour your bedroom a sky blue colour. I would go for maybe vitnage or victorian furniture,

I would also recommend this for maybe some wall art- http://www.willandglory.co.uk/PBSCProduc... and this http://static.spoonful.com/sites/default...

I would also maybe use fairy lights around the bed- https://allthatjest.files.wordpress.com/...

https://www.etsy.com/uk/listing/19409456...

I would maybe have this above the bed- (see picture)