We prefer you to create a new post when you have questions about something different than the original post of a thread. I have moved your question to a new thread and gave it an applicable title.
I assume your question is not related to a challenge at freeCodeCamp?
When you say you are confused how to go about it, can you be more specific about what you do not understand how to do?
For example, do you not understand what the end result should be? You said you need to multiple all the odd numbers of an array by 2 but are you supposed to create a new array to store them in or something else?