1. Not entirely sure if ya need a certain amount of IQ before performing the needed act for them to invent a Lightning rod. But the simple solution is just to ZZAP a human. They will automatically gain the Lightning rod knowledge after such an event. However, a heads up. I recommend you do this to a human far away from any flammable resources like trees and plants. I tend to put my volcanoes far away from my flammable resources. That way once they start smelting ore for metal, you can zap someone on their way to the smelter without causing a massive forest fire.
2. Once your humans know how to make farms, I tend to spam a few samples from apple trees(guess it works on any other food source too) after they've learnt farming. They will use the extra food surplus to successively build more farms. Be sure to help them learn about the Oven and Charcoal as soon as possible too to maximise food production. You'll most likely see more bread than any other food source, such as apple pie for example. Why? It can take some time for your humans to chop down the tree(which is the only way I've found out to harvest them manually). They also need an axe for the chopping, which requires their own time and resources to build first. I tend to mix posion berries + herbs as a food source for my population. Much faster to harvest and demands no tools, but it will only JUST about help your people to survive. You'll have to experiment and see what works best for you man.
Hope this helped!