BuddyPress.org

I’m new to WordPress and now I’m doing a project that related to buddyPress. But I don’t know how to customize the BuddyPress User Interface. The others pages I customized is using the elementor. The theme support told me that I can’t use elementor to customize it. I did some research on Internet. Some of them said need to use child theme. Can anyone tell me what should I do to customize bbPress or BuddyPress ?

Besides, I wonder what’s the difference between listing and post ?