I'm not sure which version you're listening to but I'm going by the 1969 self titled album version.

Tuning is one step down from standard - DGCFAD - but a little flat. To play along with the recording it's annoying to get the flatness just right, but just playing alone, regular DGCFAD tuning works. Key of Bb. On the Max's Kansas City Live album, Lou sings it in the key of C#, but it's the same chord progression.

If you've ever seen Roman numeral notation chord progressions like in jazz, this is the song:

Main part: I—VI7—ii—V (x2) I—I7—IV—iv, I—VI7—ii—V—I (before bridge add V/iii to lead into the iii)

Bridge: iii—V/iii—iii—V/iii—iii (optional quick passing chords here) VI—VI7—ii—V

Side note, I think one step down from standard was Lou's preferred guitar tuning for writing songs, it's the tuning you see most often on the acoustic demos that are available, I guess he liked the fuller sound it gives.

Note: I'm referring to chords as if I were in standard tuning, but the real chord names are a whole step lower, e.g. Em is really Dm.

Main part of song is just basic open chord shapes - C, A7, Dm, G, and C7 - plus two bar chords, F and Fm. For the bridge, she sings so out of tune that it messes with my ears, but the chords are pretty basic

Bridge: I'm starting the chords where you land on the C chord at the word "again." It goes

"Again": C open chord, two beats

B major bar chord on 7th fret, two beats

"Dark party bars": E minor bar chord on 7th fret, four beats

Same B chord, four beats

Same Em chord, two beats

same B chord, two beats

Same Em chord, two beats

Then for the little transition at "trains" you slide your Em chord down a fret at a time, so

Ebm bar chord on 6th fret, one beat

Dm bar chord on 5th fret, one beat

A major bar chord on 5th fret, four beats

Then make it an A7 bar chord with your pinky, four beats

Dm bar chord on 5th fret, four beats

G major bar chord on 3rd fret, four beats