Hello, What HDMI Input on the TV is your Firestick plugged into?
Also, have you used the original TV remote's "Input" or "TV/Video" button to select that input accordingly (HDMI 1, HDMI 2, etc.)?
Once you do that then you will be able to see the Firestick setup MENU and then will use the Firestick remote to access features/setup/change channels.
If you're still stuck, then please make sure you have the USB cord on the Firestick plugged into a power supply of some sort (the TV's USB port or the included power supply) and also let me know the model number off of the back of the TV.
Feel free to reply back if you need more help, or want to reply back with more details. It does not cost you anything more to reply back once you've rated. Please do rate me positively (at least 3 STARS) and I will continue with you until this is sorted. The positive rating ensures I am credited for my work.