The DT decal suggests mid-seventies Gitane Pacific issue - probably one of the more popular budget Gypsy Sport or Gran Sport models.

French bikes are really no more difficult to work on than Japanese or American bikes - IF the parts are all accounted for and in decent condition. It's just a matter of servicing it and reassembly like any other bike, BUT if you buy a rough frame devoid of useable parts, restoration becomes more of a quest than an viable economic alternative.