Finish puzzle #5 Herb Mastery first.
Next, set all 3 adults preferences to farming and let them get a stockpile of fish before the ocean becomes algae infested.
Once that happens, set all preferences to science and monitor their progress. As soon as they have enough points, purchase level #2 farming and level #2 engineering.
Change all preferences to construction and get them working on the dam.
Once the dam is complete, put 2 women's preferences to parenting and stay with them until they become trainees. Change 1 villager to farmer and all others to science.
Let the population grow to around 15 until you are able to purchase level 3 farming.
Then let your population grow large by changing one 18-year-old man's preference to parenting. Build a second hut at around population 35, first hut around population 10.
Save points to purchase level 2 and 3 science before you buy any of the other techs.
Once you bought all the technologies you should have 90, mostly adults, to finish all the puzzles.