car shakes a little when foot is on brake or in park

Can you provide more context? A brake vibration would present while braking, which is usually caused by warped rotors. Resolution would be to either replace rotors or have them resurfaced. If the vehicle is misfiring, that could be a whole host of other issues, and would require diagnosis. If the vehicle is occasionally vibrating at idle with ac on, you could just be feeling the ac compressor kick on, as it puts an additional load on the system, which is normal operation, especially on that generation of cr-v. Another common quirk of those cars is that the map (if on) lights will dim slightly, just for a split second, when compressor kicks on. When this happens, what do rpms look like? Did you recently fill up on gas?