Want to watch videos from USB stick/Plex on a TV with only an HDMI input. Suggestions?

I can't use Plex through Rogers XFinity because the dumb app (through Rogers) doesn't support personal media servers and the TV I want to use only has HDMI inputs, no USB inputs (it's an older TV) and I can't stream directly to the TV. I don't really understand Chromecast/Firestick, but it looks to be what I want(?). Can I use my own media server with Plex using those? Any suggestions would be helpful.