@Arthur Dent Many users fall into the trap of comparing a smart TV with a PC, and think that they are free to add any browser of choice, and any program (WIN32 executable, utility, or that horrible word "app") that they please. Unfortunately, a bit like Apple devices, they are VERY locked-down, and you can only install software ("apps") from the official store, in your case, the LG store.
As for a camera, again only certain LG TV's are compatible with an LG camera, and I don't think any "official" ones ares still available. A few LG models had cameras built in, but I don't know which those are.
LG DO show one for a 2011 smart TV (link below), but I doubt it would work on current ones. Your best bet is to use a camera on your PC or Laptop. Laptops with an HDMI out socket can connect to your TV, but I think that a Skype session will look AWFUL on a big TV screen..... just stick to the laptop!
https://www.lg.com/au/tv-accessories/lg-AN-VC300-tv-accessory