The only thing I can suggest is to clean your computer. You can't increase the amount of memory you have. If you want more space and have alot of Junk files and alot unused programs, Get rid of them. Download and install iolo System Mechanic. It can be done at iolo.com. Great program for cleaning and optimizing a PC. Free 30 day trial
How do you plan on adding additional hardware without spending anything?
How is that possible? Your hard drive and RAM have a fixed amount of storage that can't changed without adding more RAM or a bigger hard drive.