1. On my first Camino I didn't and couldn't train before I went. BIG mistake--plantar fasciitis that eventually ended my walk. The better I train, the more I enjoy the trip.
2. Walking in the heat. First CF, started Aug 27. Heat to almost 40C. Second stated late July--still too hot. Third, started Sept 29-- super hot until mid Oct then still hot, but not as severe. Fourth, mid May--still hot. This year, walked the Camino Portuguese starting April 10 and fabulous weather.
For some, the heat doesn't bother them. For me, especially as I get older, the heat significantly hampers my performance and this, enjoyment.