Just to keep things simple.
For ice you need two things: water(vapor) and temperatures below freezing ( air or airframe).
Dry ( clean ) air is clear.
Humid or moist air is hazy.
Increased haziness means increased humidity. Fog, mist and cloud are basically all the same, visible moisture.
Any time you’re flying in visible moisture with a measured temperature of 5 C or less you’re in icing conditions. Why +5? Because of a slight temperature rise caused by friction even at slow SE speeds and measuring and position errors of the probe.
An IR rating doesn’t mean you must fly in cloud, you may.
You may under conditions for which the aircraft is certified.
Most light single engine aircraft are really only suited to fly in ‘soft’ IFR or ‘gentlemen’s’ IFR.
Marginal VFR or simply just to climb through an overcast and cruise in clear air.
They lack the equipment to fly ‘hard’ IFR in snow and ice with weather down to the ground.
Avoid instructors that feel they need to prove something.