verifying my video works on zoom meetings

my video seems to go out when I’m on zoom meetings.   Sometimes the video won’t start, or other times in the middle of a zoom meeting,  there is a glitch,  i never lost connectivity, although there was a pop up message, then I noticed I could not get video to be visible in the meeting.  The zoom was 4 hours long and was recorded.  I left the meeting and rejoined again, but no luck getting my video on.

Is there a quick way for zoom support to test my video right now?   I just reset my computer, an hp laptop.   I also want to add a back ground picture of myself as well, I don’t pay for Zoom.