How can I share or export my SketchUp file with a friend
Easiest way is to upload it to the 3D Warehouse and give them the link. Hamburger menu at top left, 3D Warehouse at the bottom down the left.
I also see that I can upload it in private mode.
How do I download it then, using the free Web SketcUp?
Go to Components on the right side and search for it.