Does the heart get its own blood supply?

Yes, the coronary vessels supply the heart with blood. The left coronary artery and right coronary arteries arise from the ascending aorta - the first bit of the aorta.

so the coronary arteries supply it with oxygenated blood, because its a hard working organ and it needs energy does it use the o2 for respiration?

The heart is essentially a muscular pump, beating at an average of 72 beats per minute. Hence it requires a lot of fuel, and that O2 is indeed used for aerobic respiration to enable the heart to keep beating.

In my book it says restriction of the coronary artery reduces o2 and nutrients such as fatty acids to the heart which can cause angina. Isnt fatty acids bad for the heart because they can block arteries, also the nutrients is simply for energy right?