If your remote buttons are not doing what you expect them to, the remote is probably not in STB mode. Press the STB button at the top of your remote below the Power button to return it to STB mode and try again.
For normal operation, your remote should stay in STB mode. In this mode, the remote will operate the TV when you press volume keys and the STB for most other functions. The Power key will operate the TV and take the STB in and out of rest mode.
If you need to operate TV-specific functions, like TV Input, press the TV button at the top left of the remote to put it in TV mode. Remember to press the STB button when done to put the remote back into STB mode.