when you are starting, the most beautiful music is sustained tones (no cracked notes)! :-O
There are books with 3 part fanfares in them (Edition Alta Musica bei Marc Meissner-available in Europe at
www.spaeth-schmid.de for instance) or the complete Bach and Handel works in various editions. Ed Tarr has a lot available too.
Like with a modern trumpet, just take it easy - long tones, scales, intervals, pitch bending exercises help most. Don't take any jobs for it during the first 6 months.............