Radio Waves propagation (Intuitive Understanding of Wave propagation)
Do the EM waves travel by creating disturbances in the air particles such as compression and rarefaction?

No.
Radio waves are electromagnetic waves. They propagate in the electromagnetic field itself.
They do not require any physical medium to travel through and can travel through vacuum just as well (better, actually) than through air. If EM waves couldn't travel through vacuum, we wouldn't be able to see the sun.

What would be typical distance range in terms of radius (in km) of an FM/AM radio station? I tried to find. But unable to find it. Somewhere, I have read that the distance coverage is dependent upon the power of the FM Radio Transmitter? Could someone please throw some more information like a certain table which would provided the distance covered and the radius of coverage of the FM Radio?

What you read is correct: It depends a great deal on the transmitter power. Other factors such as antenna configuration, terrain, atmospheric conditions, etc., can also strongly affect broadcast range.
Normally, transmitter power is limited by regulations to allow for transmission over a few 100 km or less.
AM radio often has greater range than FM due to the lower frequencies used. The most powerful stations in the US (for example, KGO can be heard over nearly half the country, a range of well over 1000 km.
For US stations, sites like radio-locator.com provide coverage maps showing the areas stations are licensed to broadcast to.
Here's an example for one of my local stations, broadcasting with 8.9 kW from an altitude of 412 m (but in fairly hilly terrain):


If the FM Radio communication are a type of line of sight communication, how am I able to receive the FM Signal even if my receiver is not in direct line of sight of the FM Transmitter?

FM radio at broadcast frequencies is not truly a line-of-sight transmission. Due to diffraction, the signal can often be received even if a building or hill intervenes.