When i was a kid, i used to carry clubs to the range on my huffy. Here's how I rigged my "quiver"

Piece of sawn-off metal fence post pipe (Today I'd use 3 or 4" PVC)

I somehow make-shift bolted that to the axle lug. Today I'd use a braze-on and do something more elegant.

Bolted to the rack, I used about a 6" diameter hoop made out of metal strapping of some kind.

The clubs wen in upside-down and rattled around a bit, but got the job done. It was big enough to hold a baseball bat if needed.

All it carried was that clubs. If I needed to carry the bag, I don't know what I would have done. Maybe get a bob trailer? Or, hunt around garage sales for a three-wheel golf cart then rig up a hitch mechanism?