I don't know why you are adding currents...(10mA+20mA). The current in a series circuit...the limiting resistor, the LED and the SSR...is the same through all components.
For the 12-18VAC circuit: Use the maximum peak voltage: 18*1.414, subtract the forward voltage drops of the two LEDs: 3.3V and 1.2V, and use the current through the series circuit:10mA.
R=((18V*1.414)-3.3V-1.2V)/10mA=2095Ω... so use a 2.2KΩ resistor.
For the 12VDC circuit: Use the DC voltage: 12V, subtract the forward voltage drops of the two LEDs: 3.3V and 1.2V, and use the current through the series circuit: 10mA.
R=(12-3.3V-1.2V)/10mA=750Ω... so use a 680Ω or an 820Ω resistor. It's not critical.
For the capacitor in the AC circuit, I would try 10uF/50VDC electrolytic capacitor. (note the polarity)
And, I would change the 1.1K resistor across the capacitor to 10K.
Ken