Yes, you can and should keep it at room temp depending on the temperature parameters of your test. You will want to put it in the fridge on Friday night or Saturday morning. This will make the grown yeast go dormant and settle out of the liquid. On Sunday morning pull out your starter and decant (pour out) the liquid. Leaving just enough to swirl around the yeast. Let the yeast come to room temp before you pitch it. You may also want to check the amounts of DME and water. I'm not sure on the conversion to cups but you want 10 grams of DME to 100ml of water.
[EDIT] I googled it for you and 2 cups of water is around 473ml so you would want about 47 grams of DME which is about ( .1 of a pound) yes, that is a tenth of a pound not a typo.