I have a new smart TV. It is smarter than me.

LG OLED55C7P There is a plethora of icons at the bottom of the screen but I do not know which ones are good choices. i.e. FREE
There must be over 20 icons. Any help would be appreciated.
I noticed YouTube was not among the choices. I was able to access it via the web browser. Entering search requests is a pain but it works. Is it possible to sign up and save things in YouTube? I remember doing that a long time ago and then Google or some other company took over and changed things. Obviously I was not a serious user before but watching music videos on my new TV and through a good 2-channel system is fun.