You can install a new SSD into your laptop. Use this YouTube video as a guide.
Upgrading your hard drive to an SSD will indeed boost the performance of your laptop, especially when it comes to loading stuff. Like Windows should load up very fast, in a matter of seconds, other programs, like Google Chrome and Office too. It will all feel a lot smoother, as the computer has to spend less time reading data from the drive.
Upgrading to an SSD does not mean that you need to upgrade the RAM too.
Your overall performance however also depends on the other components. Depending on the amount of RAM and on the CPU that you currently have installed, upgrading the RAM would or would not make sense.
If you currently only have 2GB of RAM, sure, go ahead, make the jump to 4, 6 or even 8. 2GB just won't cut it in 2017. If you have 4GB but a weak processor (like a Celeron o Pentium from 2013), adding more just wouldn't make much sense.