How would I go about UV mapping this object? I just modeled this object that I'm going to be using in a bathroom. I tried importing it into Unreal Engine but when I do the mesh becomes black after light building. People said I have to create a UV lightmap so I looked up tutorials but first I need to UV unwrap twice since Unreal Engine takes the second UV as the lightmap. I have no clue where to start UV mapping since the urinal part dips in. I understand the top sensor part since its just circles and spheres, but its the other part I'm confused about.

Object mode:


https://gyazo.com/788809e77f70e60108258f7820b38c36

Edit Mode:
https://gyazo.com/ecbdebe1bdebc22820bbe4fab8123176

Here's a view from the inside:
Object Mode:


https://gyazo.com/0ca128321a4e9b5726f2f4e6304865b0

Edit Mode:


https://gyazo.com/5e0349a89a71de55d54bad68987847f9



Can someone please just say where I should mark seems?
Never mind everyone I did a UV Smart Project and it looks like this:



Would this be good for making the light map and stop the overlapping?