Hi Bridget Sarah I am complete newbie to web development and I am really eager to learn, therefore I am not a good person to suggest a choice for Gulp.
I am a certified RedHat Engineer and have one more certification from Linux Foundation. If you want to learn basic linux cli provided purely on linux, I'd suggest to enroll yourself in the course provided by LFS on edX. Provided you've time you can take the course by RedHat too which would be a way more beneficial to get through command line.
However my answer replies you in administrator point of view rather than development, as I am inclined more towards the administrator. However happy learning.