Welcome to Zwift and the community, Steven. Good on you for taking the leap into this world.
First things first, I don’t think there’s anything obviously wrong with your set-up, but there could be things to work on, which can help you further enjoy your time in the saddle.
I’ve found your profile in the users list and am posting a screenshot of your Companion overview of that ride (with some of the data redacted). I hope that’s okay.
It does look rather choppy (the white line is the power), but not shocking. (Just for everyone’s reference, the maximum power here was 600W.) Choppiness isn’t unusual when a rider is less experienced or has been away from cycling for some time. Training one’s body to coordinate movements smoothly and to waste as little energy as possible takes some time, even if one has previously been accomplished, so perhaps you need to concentrate on that aspect.
If you’ve been doing workouts mainly, probably in erg mode where the machine adapts to and accommodates the user’s varying power and cadence, you might not have been getting the useful feedback that could help you in reducing the variation in power output.
When I first got back into riding after a long hiatus, back in 2018-2019, I went through something similar. Maybe my ride graphics still aren’t as smooth as the most talented (and harder-working) riders’ ones, but I think I’ve developed a much more regular pedaling style over the thousands of hours I’ve put in since then.
Doing rides in sim mode, like group rides (e.g. the Pride one) or free rides – basically anything that isn’t in erg mode – is useful for that. It takes time to dial it all in, so just ride often and try to keep your on-screen avatar in roughly the same position in relation to the others you are riding with. You could also try riding with the RoboPacers (find them under 24/7 Group Rides in the main menu), which are automated ride leaders that keep strictly within a W/kg range. They increase their power slightly on uphills and decrease it slightly on downhills, but are far steadier than any human. 
The other thing to look at when one’s power output isn’t so smooth is one’s position on the bike, i.e. the fit.
If you’ve been away from cycling for a while, you might not even have a good feeling for what is “right”. Indoor cycling is great, but it can also mask what would otherwise be red flags when riding outdoors regarding what is right for you bio-mechanically, so perhaps it’s worth getting that checked out.
Changing saddle height, and saddle position fore and aft (plus saddle angle), even a little, can have a significant impact on your pedaling and the resulting power output and its smoothness. A saddle that’s slightly too high (or much too low) can often produce a choppy, uncontrolled output…
There’s also cleat position, handlebar height, stem length, etc., etc., but the relationship between the crank centre and the saddle position is probably the most important to one’s output in Zwift.
Is the bike definitely in your size and has it been adjusted for you by someone experienced?
Don’t go paying out hundreds for a bike fit just yet (or at all). Much of the information is out there for free and you can get into the ballpark on your own with a little time and patience, plus the few tools that are necessary. One of the other great things about indoor cycling is that you can experiment with your position without the hassle of doing it on the road in traffic.
Sorry for the excessively long post; I hope it’s useful. Ride On 
Edit: spelling the OP’s name correctly (!); syntax.
