Noob looking for advice

I'm almost finished with the campaigns and looking forward to having my ass handed to me by human opponents! I've watched a few SotL tutorials, but I know I still suck badly, so hoping some of you can give me some general tips so I don't get completely crushed.

I've heard that I should aim for around 120 villagers, but what proportion of those should be on food, wood, gold, stone and building?

Are there any more straightforward civs I could pick to make my life easier?

Are there maps that I should avoid or ones that are easier to start with?

I know I should set up hotkeys, but don't know which things I need or where to put them.

I constantly get stuck trying to complete all my research before going into battle - any advice on how to balance economy, military and research?

Any other general advice I should know?