Start small that way its easier to manage and learn your marketplace,
and do loads of boring research - Call or email supermarkets to find
out how difficult it is to place your product on their shelves.
Ask local independent food stores to stock your products. Put up a
stall at local farmers markets (are you in the uk?), craft fairs, food
fairs, shows and the cook offs you mentioned. Could you not do it all
from your own kitchen to start with? EHO withstanding. Or failing that
rent the kitchen space in a local pub/club that no longer serves food.
Good Luck.