There must be someone here that is working with reenactments and would be able to give you a few pointers
YO! You rang?
I don't have any experience firing projectiles. But I do have some experience with a 3lb Grasshopper cannon. We used charges wrapped in aluminum foil...1-1.5 oz was pretty typical, IIRC. We had to wait 10 minutes between sponging the piece and loading another round. It's essential that the vent hole is covered tightly to deny O2 to the breech when you are loading rounds after the first firing. Usually a guy with a leather thumbstall does this.
1) Cover vent (and hold it until charge is loaded and seated)
2) Run down the worm and pull out any scraps of whatever in the bore, also this checks the bore for obstructions
3) Sponge the piece
4) load cartridge
5) ram down cartridge
6) Remove finger from vent
7) Prick and prime the vent. We used quill tubes, you can use fuse.
8) FIRE! Ensure that you remain clear of the cannon carriage as it recoils, if it's loaded with a projectile.
Cannons are lots of fun and are always a hoot at reenactments. You won't have to use period correct gear, so there may be some modern substitutes that makes stuff easier or cheaper. We just did it the old way.
Now, at some events I've seen cannon fired at max rate and moved around on the battlefield by hand, serviced under combat conditions, and with reduced crew. Very interesting, but dangerous if you don't know what you are doing.
"The people I have heard about getting hurt doing re-enactments etc. was from putting a new charge in with a hot ember still in the barrel and blowing the ram rod out of their hands and maybe a finger or two."
Hold the implement with your palm as flat as possible, facing up and keep as many fingers out of the way as possible. And for God's sake, be careful!