Welcome mrsblue!
It looks like a pretty standard machine for threading it. From the spool to the thread guide(possibly two guides on top of the machine), down between the tension disks, back up the other side of the disks(the thread should pop in behind the spring on the disks) down under the guide to the left of the disks, up thru the take up lever, follow the guides down to the needle. The needle most likely faces with the hole front to back with the long groove in the needle toward the front.
Caroline is still active here so I hope she sees this too.
Rodney