Congrats, welcome to the club! Here's a few of my suggestions:
-Don't try to carve on anything expensive or exotic until you've got it dialed in. Odds are you'll have to tweak belt tension, V-wheels, and/or potentiometers. Practice on MDF or something cheap until you're happy with what you get.
-If you're going to stiffen the X-axis (see my video in a thread below for one method), it'll probably be easier to do that during initial assembly. You can also search the forums for "X axis stiffening" and find a few good threads with other methods.
-Look online for some of the videos that YouTube woodworkers made about assembling the X-Carve. There will be all sorts of assembly tips, problems we ran into, and alternative methods that you may prefer. My assembly tips video is in one of the forum links below.
-If you're going to use Easel, you can start using that immediately. You can design your projects and save them, which will let you knock them out one after another when the machine is dialed in.
-Finally, don't hesitate to ask questions on here. If somethings missing, bring it up. If it sounds bad, record it and upload it for us to see. If bits are breaking, smoke is showing, or something isn't working right, take pictures or video and let us know. There's a lot of "new" experience on here that can tell you what caused their machine to do the same thing.
Here's a few useful threads to get you started: