Thank you so much for your help, Jay and Deelesh!
I have another question though.
I am using OD Cost Matrix for my task and I find out once you load your locations into either origins and destinations, they are assigned new attributes, which have nothing in common with the original points.
I am just wondering is there any way I can keep some if not all attributes from the original point layer.
I know on the map, they are two separated layers, I am thinking I could use spatial join, but I am afraid it would not help much.