Problem with stress simulation on simplified model of an engine.

Hello, im trying to do static simulation on a simplified model of an engine. After many hours spent trying to set everything up and failing again and again i finally understood that i need some help from more experienced users :<

I have few questions:

Could you tell me what kind of connections and fixtures i need to make this model properly(realisticly) distribute applied pressure ?

Also i tried to exclude the engine block from simulation and only use it as a mean to keep everything connect within specified distances but then piston will move side ways

What mesh set up would you advise me to use?

I will be grateful for every help you can provide(even some tutorials which would help me to undestood simulation tools)

SolidworksSimulation