So, fret not.

Maybe if you can enunciate some of your concerns, we could help, but there shouldn't be any issues I can think of arising because you got the room.

Just be discreet down in the lobby and don't call any undue attention to yourself.

I would leave the door ajar just before she comes up so she doesn't have to knock.

Be sure to deadbolt the door after she enters, and put out the "Do not disturb.") sign.

First, I assume she has reviews here and you've done your research... If you have then I'd have some tunes playing on the IPad, a bottle of unopened wine at the ready (don't forget the glasses and opener)... Let her know the hotel you booked and have her call you for the room when she arrives... Have the door ajar so she can walk in without knocking (although most of them still knock in my experience)... Have fun!

1) Have her call you when she gets to the parking lot as that will give you a 3-5 minute heads up.

2) Get a hotel that doesn't have a key card elevator, saving you a trip to the lobby and proly making her feel more comfortable as well.

3) Ask her to dress down when she comes to see you. This is more of an issue with younger and/or inexperienced girls but it never hurts to mention it.

4) Make sure she drinks before you surprise her. Some gals are recovering alcoholics or just feel uncomfortable sharing alcohol in a first meet session.

5) if you aren't staying overnight, make sure you get there early just in case you hit traffic or if she happens to get their earlier than normal, but again, the latter is almost never an issue with experienced/more professional types.

6) have some cold, bottled water for h

you or she can open them together, so she's assured they are not tampered with.  Even civies must beware this it seems (very sad).  In this game we love to play...  there must be an element of trust in both direction.  Do nothing that will undermine her trust.  
I would say to prop the door ajar on the night latch when she calls.  No PDAs before the door is latched...  Repeat appointments we sometimes are wrapped up in each other against the inside of the closed door.  When you come up for air...  place the Do Not Disturb sign & lock the door & night latch.
I like to have soft soap for hand washing & bring a couple of real bath sheets if showering is anticipated.  I hate  the tiny things hotels try to pass off as towels.  
If it is to be an extended visit, you might want to include refreshments.  Check if she takes alcohol as stated above.  
I like music...  aimed at the door to cover sounds...  not thumping in my ears so I can't focus on the delights at hand.  
With any "first date" I prefer to place the donation well into the room, God forbid she a cash & dash scammer!