We have a '17 Axis 25.5. Our TV splitter is located behind the microwave, which you'll have to remove to access it. The plug for our microwave is in the top of the cabinet above the sink. You'll have to unplug it and push plug and cord thru the hole in cabinet wall that goes in to area behind microwave. Be sure to have a helper if you remove your microwave...don't ask how I learned that the hard way.
If your coax cable isn't connected to the TV, you aren't connected to the antenna. The HDMI cables are for AV input, such as a DVD player, x-box or video games. Thor puts the cable in but you have to add your own AV toys. As to the TV wall mounts, the ones on our bedroom TV and outside TV have magnets that hold the TV's close to the wall. Gently pull on a corner of your TV and it should pull away from the wall so you can get to the cables. As previously mentioned, cables are often not tightly connected, so be sure your's are. Good luck!