Question

"Last month, I traveled for business, pleasure, and community service."

Not sure if this is a correct parallel structured sentence, help plz

Answer 1

parallel structure means the parts are "parallel" in how they are worded. (That's not how the grammar books might say it...) Two different sentences that use parallel structure:
Last month I traveled for business, for pleasure, and for community service.
or
Last month I traveled for business, I traveled for pleasure, and I traveled for community service.

Do you see the difference? Look at the wording and what is the same throughout.