You will need some special bike tools- a crank puller, pedal wrench, allen key set, chain breaker, a bike stand. Japanese bikes made in the 80's are the easiest to find parts for. Almost any bike that old will need new cables, a seat, bar tape, a complete bearing regrease, maybe a chain, tires...the initial price is just the beginning.
Good luck.
If you want a French bike because of their comfortable ride, classic styling and prestige of ownership.. ..get one from the late 80's as by that time most of them had standard thread sizes.