Can I have a Stafford Loan, meant to cover two semesters, pay for only one semester?

I am on a fixed income. I collect SSI disability and am out of school. So it is easy for me to save money. Once I am in school, I will be outside every day nearly, and i will likely spend more money. I am taking advantage of my sedentary life right now to save to get all the parts for christmas so i wont have to micro budget and buy the computer in 2018. I really dont want to have to save for that long just to buy a computer so i am trying to buy it near the beginning of the spring semester.