Is adjusting a noun

Yes, the Word 'adjusting' is a gerund, the present participle of a verb that functions as a noun in a sentence.

The present participle of the verb also functions as an adjective.

Examples:

Father was adjusting something under the hood of his car. (verb)

Adjusting will take some time. (noun, subject of the sentence)

The adjusting lever should be right in the center. (adjective)

Other noun forms of the verb to adjust are adjuster and adjustment.