To install Steam on most distros with popular DE’s, you click the software store to open the software store. If Steam isn’t listed in the front page then just click the search box and start typing Steam.
When you see it, click the install button.
When it is done open it by clicking the Open button or pressing the Windows (or Super) key and type Steam. Click it when you see it.
Your lungs can aspirate both Pg and Vg (derived from vegetables). It is misleading in my opinion to call them oil in an effort to make them sound dangerous. Pg is not petroleum and has been considered safe by the medical community since before vaping was a thing.
What makes it an oil? Viscosity? What’s the viscosity that makes a liquid an oil? You inhale water as steam but that doesn’t make water an oil.
You can call it an oil in general but just like when someone refers to electromagnetic frequencies (EMF) as electromagnetic radiation (EMR) I already know they are very likely to fear monger about it because it sounds scarier.