Okay…I might have seen what happened there…couple of things.
1. First you need to open the lid, pull open the front drop-down door, and shift the tray forward until the little feet seat themselves in the dimples in the bottom. It’s sitting too far back, i can tell from your picture…too much curve is showing on the front tray handle. That should snug up into a recess in the drop-down door.
2. Second thing - make sure that when you place the material on the tray, you do not let any part of the material overlap the plastic edges on either side of the tray.
You have to keep the material only on the metal grid part of the tray. (If you think about it, you don’t want the laser firing into plastic. ) If the material extends over onto the plastic part, the wheels from the laser arm can catch on it and that causes the arm to get stuck and the stepper motors to grind/grumble. (We call it grinding.) That can throw off alignment big time.
So what you need to do to start is make sure the tray is seated down in the dimples, and do not place material anywhere except on the grid portion of the tray.
3. (You can quit cleaning the lenses now - they haven’t been in use enough to experience any buildup yet.) 
One thing I do want to caution you about - be gentle when you are cleaning lenses, and do it as little as possible. I clean them about once a quarter. And if the lid camera is loose or turns when you wipe it, you need to notify support immediately. That is supposed to be glued in place to keep the focus set. If it turns, they’ll want to know.
4. To calibrate the machine, you need to put a sheet of draftboard inside the bed of the unit first. Follow the instructions here, placement of the material on the tray is important:
https://app.glowforge.com/maintenance/camera-recalibrator
Where you are getting the all white screen, if you look in the upper right hand corner under your name, it gives you instructions. It wants you to Select the Material. (Since it can’t see the QR code underneath.)
Click on Unknown in the lefthand column, and use the little search magnifying glass to select Medium Draftboard. Then continue forward. There is a video of the Calibration process here that you might want to watch first before attempting it.
5. By the way, the little Red Dot on top of the gift next to your name on the Dashboard means that there’s a Glowforge freebie file waiting for you. Click on the red dot on the Dashboard gift to download it. 
6. You can’t. There is an overlay deliberately placed by Glowforge that keeps people from placing their designs anywhere except on the cutting area of the bed. You cannot cut all the way to the left or right side of a sheet unless you turn the material 90° and feed it through the Passthrough slot. (It’s very useful for that though.)