Spring: Work on several wagons. Keep farming mushrooms. Attempt to grow the grain when the season gets warmer in a muddy above-ground plot. Keep working on the council hall and the archery tower. Keep taming the goats. Send one person to attempt to map out the nearby area. Make some weapons that are easy to use, for training. However, also work on a bow that is long, and gives great range.
Summer: Send out a larger caravan of about 20 people to make a new town about a season and a half from the current town, in between the other tribe and us to serve as a trading post. Do this as soon as possible, and take enough mushrooms to last a year for 20 people, as well as weapons. Keep farming mushrooms here, and taming the goats. Keep working on the archery tower and council hall. Make a life-sized statue of the leader, to put in the council hall. Keep attempting to farm the grain. Try to look for anything that isn't stone or soil when digging.
Autumn: Work on some kind of channel system that would allow people to control some of the river's flow, and siphon it off for water for mushrooms or the grain in winter, as well as to drink. Keep working on the archery tower, as the council hall is probably finished by now. Keep farming mushrooms and taming the goats. Harvest the grain, if it grew. Praise the god of plants if it did. Build more houses if the archery tower and water system are complete, and try to expand mushroom farming.
Winter: Keep farming mushrooms and taming the goats. Don't farm the grain. Work on a wagon frame and wheels. Work on another warehouse if everything else is complete. Try to come up with some kind of body protection for militia. Create more crafts to trade with the tribe.