RE: I think I must be making a big newbie mistake.
I get in my stand early, by 5:30AM. I have a stationary stand so it is not difficult. I usually spooke a couple deer getting in, no way to avoid it sometimes. Usually though by the time legal shooting hours come around the area has settled down and deer will come in.
You may have other problems such as sent control etc. that prevents you from seeing deer. That may be why you did not see the two before. Do research on that, I can't express that enough about scent control.
The deer may also be moving more at night in your area but do your reseach, read through post and be patient. If you are new to bow hunting I would suggest you place a stand in a spot you are seeing deer and stay put.