Taken from the specs in the PDF:
Support for 2 PCI Express ® x16 Gen 2 graphics cards up to 150W.
Up to 150W? That might not be enought to mine with good GPUs.
If you are really interested in mining I suggest you buy cheap second hand materials first:
Mobo (something with at least 4 PCIe slots), PSU, ram, HDD (SSD), ...
At least something decent to start with. This Dell is not great to start, even if you have a small budget. What is your budget BTW?
If anything should be bought "new", it would be the GPU (like a GTX 1080 Ti, AMD Vega, ...). Try watching local ad sites; Perhaps you can buy a "new" GPU cheap.
Don't spend too much on a metal/wooden mining rig. Do as I did: Buy a cheap 20 dollar / euro metal rack and be creative with it.
http://tools.you-stupid-woman.com/miner1.jpghttps://www.hubo.be/nl/p/rek-150x75x30-cm-metaal/579712.htmlDon't use desktop or tower cases: You will need extra fans to keep the inside cool... Which will add up in electricity bills. Just use an open frame like everybody does.
Just my 2 cents.