When I launch the game I only see about 3/4 of what I should and the whole thing is shifted to the left. I'm not sure how to fix this? Changing my computer resolution doesn't make a difference. Help?

Try a different DOSBOX resolution.

Open up dosbox_xwing.conf in a text editor, find the line fullresolution and change it to fullresolution=0x0 to mke it use your desktop resolution.

Note that this might make it run slower, change the line output=overlay to output=opengl to use hardware scaling.