orbital mechanics & pathfinding for AI

I’m trying to set up a game with Interplanetary travel. This would have the AI increase it’s orbital speed to an escape velocity. Then when in orbit of the sun it would increase or decrease it’s orbital speed to match the planet it’s trying to go to. Now it would set up an intercept with the starports that it is delivering things or picking up items from. It may also just set a close orbit for dropships to go up and down from the planet’s surface. The question here is does anybody know of any kind of tutorial that would help me set up the blueprints to get this to even start to work real simple no fancy flying? I love realism but in this game I’m going to have to use ion engines with super high thrust to fuel ratio.

thank you for any help plus your time and patience.