If you want to become a Sysadmin - and keep in mind this is only from my own experience - you may start by knowing that The Many Faces / branches of SysAdmin Work are a good starting point to know what you can put / expect / use on your Resume. You should be avoiding the Classic SysAdmin / IT Misdesigns at all times, if you need to recap on those.
If you are starting a new job as a Sysadmin, either as your first gig on moving to a new company, there is this nice summary points of Starting a new role as a sysadmin - things I need to discover. Just don't forget the “The 10 Tenants of IT”. If you are looking for a new job, maybe check some questions you could ask in an job interview.
If you want to focus more on the cloud, you could always ask "How do I learn to be a Cloud Engineer?"|. Maybe a RoadMap to DevOps?
If you want to check some FOSS software to deploy on your HomeLab, maybe have a read at SysAdmin - IT Landscape.
Wondering how you can turn you SysAdmin (Ops) job more like a DevOps? Then take a look at DevOps - Improving and Automating. Maybe you want to learn better ways to communicate to non-Technical people.