I've worked as a DevOps engineer for about 6 years now. I love the field and am content with the work that I do. I realize that from the number of years experience I have, I have absolutely no soft skills. My boss has asked me to look into Project Management training and I can appreciate looking into this as it will help me do my job much better. My question is: What would Project Management really set me up for long term? Is this to advance myself as an engineer or is this more of a management skill? Ideally, Id like to stay in Engineering and hopefully see myself as a Principal Engineer one day. Can training for Project Management (PMP, Scrum Master training, etc.) get me to that point? Would this be a benefit of me to take this kind of training? And if so, what are the pros to this?
I would have loved my developers to have more project management knowledge. Even if you never work as a project manager, for you to understand about dependencies, risks, critical path, the steps that happen before and after the "dev" part, how to communicate progress in a way everyone can understand, and all the rest of the things a PM should know -- that will make you a much better developer and engineer.
That said, your boss may have a different reason for suggesting this course. They may see you moving into management, or they may just have a training budget to use up and this is something on offer you haven't already taken. By accepting this course you may be signalling a willingness to take a particular career path -- or it may mean nothing at all. I suggest you ask your boss why this particular course comes to mind and what your boss thinks the benefit to the team will be of you taking it.
Ideally, Id like to stay in Engineering and hopefully see myself as a Principal Engineer one day.
I don't see Project Manager as a step towards Principal Engineer. You would learn some useful skills, but many are irrelevant. As you progress in responsibility in Engineering you learn a more focused skillset.
One issue I have found is that when you stop focusing on a core skillset it can be difficult to go back to it. At the very least you normally would need to change companies and possibly take a job which is a step backwards.
But I suggest you read up on Project Management, it may appeal to you, and it's a solid career.