I was playing in a traditional jazz band in a Cambridgeshire pub when a young man in the audience told me he was a trumpet player and wanted to learn to play traditional jazz. Could I please lend him 'the music'?
Unfortunately, it's not that simple. The 'music' has to be inside your head. It takes months to build up a repertoire and much of your learning may have to come from picking tunes up by ear, as many of the old-time tunes are virtually unobtainable in sheet music form.
Over many years, I have built up a bunch of fake books. They can be quite expensive when new; but I have noticed recently that plenty of them are available on internet auctions, so you should now be able to pick some up cheaply. Simply type 'Buskers' Books' or 'Fake Books' into your search.
It is also possible - if you search - to find downloadable books of tunes, sometimes generously provided by particular bands.
Also be warned that, when you come to play a tune with other players, you may find the band uses a version with slightly different chords or melody notes from those in your fakebook. They may even use a different key. So be prepared to adapt.
The book Playing Traditional Jazz, by Pops Coffee, is available from Amazon.