Is there anyway through SEM to monitor your servers for memory usage, processor usage, and harddrives? Basically looking for a way to set up alerts for servers when they are getting low on memory.
Not through SEM. If your servers wrote an event to a log when resources got low, SEM could theoretically capture that, but server resource monitoring isn't SEM's function.
The Orion platform would be what you are looking for.
If you want to monitor the activities in real-time, I would recommend SolarWinds NPM.
Please refer to the below link, and you will need some scripting knowledge if you want to capture details using SEM.
https://clusteringformeremortals.com/2018/10/18/step-by-step-how-to-trigger-an-email-alert-from-windows-performance-monitor/