I am new to InDesign, as I've been creating all my documents for print in Acrobat as a PDF. When I am placing an image, it appears pixelated.
This is an expected behavior, when you place an image in InDesign then it display the preview of the image however you this has no impact on the output unless the image placed is of low-resolution itself.
In order to have good resolution of images, you may switch to View > Display Performance > High Quality.
Ding! Correct! Thank you for that.