Can I connect TV internal Speakers to 3.5mm plug?
If you're trying to connect raw speakers to a computer, you can't do that. The speakers require a lot more power than what can come out of a computer. The computer can put out enough power for a pair of headphones, which you can only hear if you place your ears right next to it. If you tried what you wrote in the OP, you won't get much volume out of the speakers, and you also risk breaking your computer audio output.

You should get yourself an audio amplifier. You can get one at a store, or you can make your own. There are plenty of tutorials online to make the latter. Here's one I particularly like: https://www.youtube.com/watch?v=3dQjIeYoIdM