Deleted skeletal mesh by accident

I have been following this unreal tutorial & i have made 2 mistake

1, I accidentally deleted the mesh details so when i go into my sk_mannequin_skeleton there isn’t an actually skeleton just a gray page - YouTube around the 10:29 mark that skeleton & what is on the left side doesn’t show just the icons above it & the rest is just a blank gray screen.

2, i accidentally deleted the options that pop up on the left side of the screen when you go into sk_mannequin_physics assets an unreal engine please help