To create your voiceover narration, you'll need a quiet, sound-absorbing location. The easiest solution is to build a temporary recording area simply by hanging some thick blankets or fiberglass insulation on two joining corner walls. If you can create something like a four-sided, blanketed cubicle, so much the better.
It is an old audio myth that egg cartons, carpeting, and foam rubber work well. Avoid them.
If you drape the blankets only in one corner, point the mic
toward that corner, place yourself between the mic and the corner, and speak
away from the blankets. It seems counterintuitive, but the mic is sort of like a camera. It "
sees " what's in front of it. In this case it
sees your face and the hanging, sound-absorbing blankets.