How to format external portable SSD X200 Kodak drive to become temporary startup

My current internal drive in my MacBookPro is festering with all kinds of malware. it got to bad that someone found a backdoor that would automatically log him/her in every time I logged in when getting online, They would then take full control of the computer, erasing half the characters and thus corrupting the keyboard, making it impossible to even buy anti malware software to thwart their hacks. This leaves me no choice but to completely erase the drive. However, before I do this, I must first remove all my personal files and work , that in some cases goes back way more than 10 years. To do this, I bought a Kodak Portable SSD X200 to copy and store all my data files while I erase the drive and reload OSX. Though I plan to us TimeMachine, I/m old fashioned and still believe in hard copies. My problem is that the software available on the Apple Rescue Site will not propely format my SSD drive to load a backup version of OSX to use as a backup drive. What do I do? How can I solve this problem?