If you need to turn on your Samsung TV without a remote, you can do it either by using the buttons on the body or by using a smartphone app. You can also use voice commands, universal remote, Mobile IR Blasters or third-party apps on your smartphone.
If you have lost the remote control of your Insignia TV, you can still control it using the buttons on its case, voice commands, a smartphone app or a USB keyboard and mouse. Alternatively, you can buy a universal remote control or a streaming device whose remote can also be customized to control Insignia TV.
QN90C and QN90B offer excellent picture quality, and great brightness. My preference leans towards the QN90C due to its IPS panels. However, if you find a good deal on the QN90B, it's still a solid choice.