Is trying an adverb?
No. Trying can be a noun (gerund), a verb, or an adjective.
It is the present participle of the verb to try.
To find the comparative of an adverb, find its root word. Once you have the root word, conjugate it for more. For example, if you are trying to find the comparative for 'quickly,' first find the root, quick, then conjugate it for more quick: quicker. (If you are asking how to make a comparative adverb, it's just more adverb. For example, more quickly.)