94 Legacy 2.2, when parked Rpms go up and down. Also misses/chugs sometimes when pressing gas pedal down more (while driving). Any ideas where I should start? Thank you

Best lace to start is with a tune-up if it hasn't had one recently.

Plugs, wires, PCV valve, air and fuel filters. Check all of the hoses for the breather and PCV that run from the valve covers to the intake tube and to the manifold.

 

If you never use fuel system cleaner, a bottle of the Lucas stuff works really well for the cost. (I usually buy a couple bottles when its on sale)

 

Also get a can of throttle body and air intake cleaner and spray out the IAC valve, and clean the throttle plate and bore.