Hiya Becky

Most wheels which are suitable for robos come on their own stand - so they are free standing and can be placed anywhere in the cage.
The waterbottle can be tricky, but it might be possible to create a small hole in the side of the bin so that the water bottle spout can be pushed through from the outside. The bottle can then be attached to the outside of the bin by cellotape or by a piece of wire, but you probably need to make two tiny holes for the wire.
To create the holes there are a few different methods that different people use - my husband uses a drill to create holes in lids for me, so i am sure it could work well for the sides too, but just be careful that the actualy plastic isnt too cold, as the drill can cause the plastic to crack if the plastic is cold and brittle, but placing it near a radiator for a few minutes first should make it ok.
Another method that i know some people use is a soldering iron - we have also used something similar, a screw driver heater up and used to push holes through the plastic, this works just the same

Please, please, please ask your parents to do this for you though if you are planning to use any of the above methods! I find it difficult myelf - either my dad helps me, or my husband, and i am 24, lol, so it might be a little tricky as you are only 13! but please do ask your parents, i am sure they would be willing to help, as this method is much cheaper than going out and buying a new cage! Please be careful! and let us know how you get on

Tammy x