Vga or hdmi?

Hello, I have a older flatscreen tv with vga output. I bought a vga to hdmi converter, which also has a usb connection option. I'm completely confused as nothing is working. The usb port is not recognizing the not smart tv, so i've tried using the hdmi cable to connect from the converter to the computer. No signal. I've tried changing the computer screen output. Nothing. if i use the vga/hdmi converter on my smaller, smarter tv, it works straight away