This really depends on what you are looking to get, but I think that I have something like what you are looking for.
First option - you don't get the "From" in the Content Editor until you've selected a field with a related timestamp in the table.
After you've added that, and submitted the change, then the "From" field becomes available.
Second question - I'm pretty sure that the field you are looking for is under Node\Hardware Category\Hardware Sensor.
Thanks KMSigma, really appreciate it!
Once I find a metric with history will Solarwinds automatically show me the average when I choose a time duration? If I choose a week will it show me for example the average temperature over that week?