Hymne a l'amour is a four beats to the bar song, and as often in French songs,has a three part structure: opening section called refrain, middle section called couplet (from the rhyming scheme), and concluding refrain in the same form as the opening. The chords are:
first refain - G/B7/,Em/Em7/,Am/Am7/,D/D7/,G/Gaug/,C/Cm Cm6,G Em Am Am7,D7///,G/B7/,Em/Emaj7/,Am/Am7/,D/D7/,G/Gaug/,C/Cm Cm6,G///; (Couplet)Em B7 Em/,C D7 G/,Csharp dim C7 B7/,G D7 G/,Em Am B7/,Csharp minor/B/,Em Emaj7 Em7/,Em6 C Em/, Fsharp7/B7/,Am7 D7 Gm7 Cm7, Fsharp minor7flat5 B7 Em Em7,Am/D13/; (then repeat as for opening refrain).
I can't help you with the tune in this format. But if you listen to the midi above, or a recording, then start Le Ciel Bleu d c b (the last note on 'bleu' being the first note of the first bar proper, then 'sur nout peut s'ecrouler (notes b b dsharp, f,a, g) you should be able to develop from their by ear.
Best of luck. If all that seems daunting, then it may be back to frere jacques as wisely suggested above.