Hi,
For anyone opening the project, the files are located in the ‘Developers Folder’ which may be hidden. - There is an option to show the developers folder in content browser settings.
(the question mark was next to simulate physics, because after dragging the skeletal mesh into the world and simulating physics nothing happened)
I was able to prevent the bike from falling through the ground by changing the ‘Physics Type’ on the wheel from “Kinematic” to “Default” and ‘Collision Response’ from “Disabled” to “Enabled” - But I haven’t had a chance to run through that entire tutorial video I linked previously, so I’ll need to double check that for any conflicting instructions.