Colera is quite empty, while Llança is a small town with restaurants and all facilities, so you can have lunch there. Some tips:
- take sun protection, even in winter. Hats are good for your head.
- take water with you
- double-check the trains; stations are small and not all trains stop there. It's about one hour away north of Girona.
This is the link for local trains:
In wikiloc you find the gps of the route:
You can install wikiloc on your mobile, and it makes it very easy to follow the track. You have to buy the app, but I believe it is worth.