Your RPi is likely sporting two IP addresses because it has two network interface controllers (or NICs), one for Ethernet/LAN and one for WiFi/WLAN each.
Each NIC has a globally unique MAC address, so what you see in your screenshot is normal.
(As a side note: Since a MAC address is designed to be globally unique, it can be used effectively to identify and track you (or your computer, more precisely). If you are privacy aware, you should not share MAC addresses publically.)
With regards to Youtube, blocking embedded ads is almost impossible by means of Pi-hole, as the bulk of them is getting served by the same domain as the content.
There are users creating blocklists and regex filters to sift out some of them, but that is a long-lasting cats-and-mice game between blocking attempts and Youtube/Google/Alphabet getting aware of them.
If you want to partake in that game, have a look at How do I block ads on YouTube?.