Look for firefighters. On two of my caminos, I was fortunate enough to be walking with several firefighters and they had the meal thing down to a science. One one of those caminos, I became the one who bought the ingredients they asked for and got people to chip in. This did not involve high finance since the meals were cheap and people are generous. The other time I fell into the role of doing the chopping and clean-up as the meal progressed. One thing I will say is that whatever contribution you make, it's rarely tedious because you will be doing it with others. Washing dishes is actually fun when it's done as a group. So, I'll have to tell my mom that her idea that the kids should do all the clean-up after supper in the days before dishwashers was actually a clever way to increase sibling harmony and engagement.
The other bit of advice is that when people ask you if you want to share in the meal, say YES (assuming it appeals to you) even if you haven't contributed anything. Your turn will come the next day or the day after that, but I think some pilgrims are reluctant to appear like freeloaders and don't accept offers to join. Most of these communal meals are huge stews or pots of pasta and seem to multiply, like the fishes and loaves. Buen camino, Laurie