It sort of looks like dry rock.
Try googling pictures of dry rock to see what it should look like. "dry rock" is essentially live rock that has been dried out, and some of the better establishments would boil it/sanitize it.
The rock should be pretty light for it's size, due to the fact that it should be very porous, with holes and caves all over it.
Essentially, "live rock" is just "Dead corals" that have calcified and turned into rocks, and live rock needs to be wet. It's called live rock because it's covered in hitchhikers, and "live" organisms, essentially the most important of all, is the beneficial bacteria that it's covered with which is important for the nitrogen cycle to take place. This bacteria pretty much acts like the filter for your tank, which will turn ammonia into nitrate.
What makes you think that the sand is "live"?
If it were live rock, I would advise that you should fill up the tank half full of water first, then add the rock, to see how much water is displaced from adding rock (there's a possibility of the water overflowing if you add too much water first due to the weight of the rocks).
Either way, in your case, you can add either the rock or the water first. Since it is dry rock, it should be fine, and even better if you did rinse it off first, to get rid of as much dust as you can. The less dust in your aquarium, the better. Similarly, since the rock is "dead" or "dry", you can mix the water in the aquarium directly.
Always add the sand last. This is due to the fact that if you add rock after the sand, it might not be as stable on the bottom (if some bottom rocks are nestled on top of sand, and that sand were to move, it can move the bottom rock, causing them to fall/crash). It's more stable to add the rocks first, make sure everything is stable, and then add the sand on top, so that the rock is always resting on the glass bottom of the tank.
To answer your question, do you have any pumps? like powerheads or anything to circulate the water? or just the filter? I would suggest turning on only the powerheads to get the circulation going for a few hours, even a day, and let the sand/dust settle as much as possible before you turn on your filter.
Do a bit of research on aquascaping, and see how you want to set-up your rocks. Some people actually do their aquascaping outside of the tank using glue/putty/zip-ties/etc, to make sure everything is as stable as possible before putting them in their tank. Take your time with it, and have fun.
Good luck.
One not-so-positive thing is your cycle might take longer. No biggie.
