Desk- in a studio there is not a lot of space so having a specific area to do schoolwork is very helpful
Rug- having a rug makes everything seem so much more homey and cozy. It makes the space look more divided from the rest of the apartment
Curtains- having curtains might seem obvious but I'm talking about curtains that will separate your bed and your living space. You can also get bookshelves that will help
Color theme- since your bed will most likely be seen having a color scheme that ties in both rooms makes everything seem more purposeful
Under the bed storage- Studio apartments don't have a ton of storage so having the opportunity to store things under your bed is helpful and also a lot of storage in your closet would be nice too depending on the size of it.
More storage could be found in a coffee table or a TV stand. You could even find storage under the couch if you buy the right one.