To determine which syllable of a word is stressed, try saying the word aloud and listening for which part you emphasize most. In this case, both nouns have stressed first syllables while both verbs have stressed second syllables:

CONduct (emphasis on the first syllable) is the noun, meaning a standard of behavior, while conDUCT (emphasis on the second syllable) is the verb, meaning to cause, to direct, or to convey.

PROduce (emphasis on the first syllable) is the noun, meaning agricultural products like fruit and vegetables, while proDUCE (emphasis on the second syllable) is the verb, meaning to create, to cause, or to provide.

Your teacher may have a specific way he or she wants you to mark stress. One strategy is to use all caps as I've done above. Another is to draw a downward curved line (like a smile) over unstressed syllables and a upward slanting dash (like an accent mark) over stressed ones.

In the four words you're asking about, the verb forms put the stress on the second syllable, and the noun forms stress the first syllable. Let me use boldface/rom type and caps/lc to show you what I mean. The stressed syllables are capitalized and printed in boldface type:

verbs: conDUCT and proDUCE

nouns: CONduct and PROduce

Webster's dictionary labels stressed syllables with a  '. So the phonetic spelling of the noun form is \ˈkän-(ˌ)dəkt\. The phonetic spelling of the verb is \kən-ˈdəkt. You can listen to the pronunciation of each word at the web site link in the sources section.