Not sure how to use Digital Ocean. What concepts should I study?

I am a front-end developer and so I don't have a lot of experience with the needed skills required in order to use the features of Digital Ocean. I understand they have many tutorials. That's great but I'd like to sit down and know the general concepts involved. For example I have no experience using SSH. I have no experience setting up a LAMP stack. etc.

My background is more focused on UI, interaction design, design, vanilla JS, and CSS.

Suggest books or overall training resources I should in order to wrap my head around using a service like DigitalOcean.