Wiring Ring Floodlight Cam

Hi all, I just got Ring Floodlight Cam Wired Plus with motion-activated 1080p HD video, Black (2021 release) and need some help with wiring. Removing an old light fixture at the door, I got two grouped pairs of wires: (red and white) and (black and white); see photo for the outgoing 4 wires. 1. Are red and black here active while whites nuteral? What the right 4-3 map to the green-black-white on the Ring cam? 2. Can I mount the metal crossbar bracket directly into the wall, or I need a compatible 4” junction box?. I worry the mounting bracket won’t fit unless I put a junction box first, right? Thank you sooo much for your help!!