The PIC is the one most responsible for all of that. Then most delegate it or the Ops state that the FO may/will conduct the Walkaround if the PIC delegates.

Either way I have seen many CA and FO do the walk around. When I was new I even had a few do it with me to show some areas that pose issues at times that were not covered in the initial training.

There are some great mentors out there. And they still walk around, share their experience, and help transition you to the left seat.