To be a well-rounded tester, you definitely need to know your way around your computer. You need to know the difference between a hard drive and a motherboard. You need to know RAM, memory, cache memory, CPU speed, overclocking, and other terms.
You have to devise new and creative ways of exploiting any possible errors in code. Developers will hate you but that’s part of your job. Part of your job to take their baby, their pride and joy, their beautiful GUI backed up by glistening lines of code and say “This doesn’t work”. I suggest you learn tact or otherwise never leave a beverage unattended.
Your brother’s roommate’s sister told you that she used to work with a guy on the night shift at WaWa, but he took a course and became a software tester. He got a job that pays $70k a year. Pshaaw! You say. No, really, she says.