To get your remote to work, you usually have to program it using a number that usually specific to one manufacturer. When you program the remote, you point it at the tv, hold down the power button, and then enter the code. When the right code is entered, the tv usually turns off. You can then turn it back on with the newly programmed remote!
You can probably find the code numbers by googling it with the name of your tv manufacturer. It may be just as easy to point the remote at the tv, hold down the power button and then start entering numbers 10, 11, 12... ...33, 34... etc. etc. You may have to release and then re-push the power button each time you try a new code.