That's not exactly the clearest of questions, Henry!
At a bit of a guess though, I'll assume that your TV isn't automatically switching to show the output from the player when you insert a DVD into it. If so, you need to change the source that the TV is taking its signal from:
Press the 'Source' button on the TV's remote control. (It might be labelled 'Source', 'Src', 'Input', 'In' or similar, or simply show a rounded rectangle with an arrow pointing into it:
https://www.svavnc.com/wp-content/uploads/2019/10/remote_source.jpg )
Use the arrow keys on the remote control to get to 'HDMI1' (or whatever else the input for your DVD player is called) and press the 'OK' (or 'Enter') button on the remote control. Your TV should then display the output from the DVD player. (To get back to normal TV, repeat the process but select 'TV', or 'DTV', as the source).