If you bought it direct from Dell and haven't made any changes you should already have the OEM 850w psu which is sufficient for most GPUs (Dell didn't sell the 1080ti with a 460w in this model). Otherwise you'd need to find out what your specs are.  You can check what it shipped with on Dell.com by entering you service tag on the lookup page 
I have an Aurora r8 with a etc 1080ti. Yes it’s a little dated but handles task very well. Wondering if it possible to upgrade to a more recent GPU and what would go along with it. Is the power source sufficient enough to handle an upgrade? I don’t much about computers all together so any information around this general concept would be greatly appreciated. 
Aurora R8, GPU upgrade from GTX 1080 Ti?