Glen's New Complete Bicycle Manual, April 13, 1987 edition. This is an excellent repair manual for vintage bikes of all kinds up to about 1987. You may want to add other repair books eventually but this is very complete and will always be useful. It's very inexpensive when purchased used - $6.36 with free delivery on Amazon:
https://www.amazon.com/Glenns-New-Co.../dp/0517543133