The words "there is" are understood. The phrases "multitude" and "many people" mean the same thing. AT: "There is the noise of many people in the mountains" or "There is the noise of a great crowd of people in the mountains" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
The words "there is" are understood. The words "kingdoms" and "nations" here refer to the same thing. AT: "There is the noisy commotion of many kingdoms gathered together" (See: [[rc://en/ta/man/translate/figs-ellipsis]])