You cannot connect Roku TV (output) to another device providing output (your DVD player).
Let me try to clarify this. I also think the red and white connectors on the Roku TV are most likely RCA-style connectors for stereo analog-audio output. They might be used to connect something like an amplified sound bar to the TV, to get better home-theater sound.
The Blu-ray player's analog audio outputs should not be connected to the TV's analog audio outputs; that would be like two people talking at the same time and no one listening.
The Roku TV, being a type of "smart" digital TV, should have several HDMI inputs. Isaiah should connect one of the TV's HDMI inputs to his Blu-ray player's HDMI output. If it's not obvious, Isaiah can use his TV's user manual to find where the HDMI inputs are located.