The log contains the details of the last time the game was opened. So if you have a disaster, as long as you check (or rename the log to archive it) immediately (i.e. before you start the game again) it'll have the information.

It'll take some practice in discovering the best order to buy the tech upgrades and which tasks to assign your villagers. But that is part of what makes this game fun! If it was easy to solve the first time through, it wouldn't be as popular.

Most of the time that I start a new game, I'll pause it at key points if I'm going to be away from the computer. But there is a point where the village will survive on their own for hours, or even days at a time.

Good Luck!