Yup yup record yourself singing separately from the recorded/mixed version of the cover and then sinc both together. I've seen people use custom stills with lyrics scrolling as well, but the general consensus I've seen is to record yourself singing for optimal interaction with peeps. I'm going to start recording myself this month too - just got a new camera for it

I've done the still video way and it doesn't have as many views as live perfomrance videos I have on my channel as well, so I think there is something to recording yourself singing lol.
You can also just use some stock video footage, or go record nature footage or something outside and make a music video that way!
If you ever want to record yourself singing without any extra editing, people usually just label those "Live cover" and then the viewer knows they'll be watching a video like that. But the majority of YouTube singers do the record themselves separately for audio and video setup.
Hope that long tangent helped at all XDD