The first time I turned on Zoom, I scared myself! It wasn't a very flattering video. It is actually pretty easy to set things up so you look your best and feel comfortable on Zoom.
1) Make sure you have a soft light facing you. Set up facing a window in your home, or use a soft lamp. It will make a huge difference.
2) Make sure you raise your computer/laptop/tablet/phone up so the camera is just above your eyes. The angle is much more attractive, your eyes will be open, and other participants will be able to see you.
3) On some devices, Zoom gives you options to adjust your appearance. See your Zoom settings but the first two tips will get you the same results or better.
4) If it is important to you, consider buying a "ring light" to look your best. They sell in many places online, including Amazon. Look around, I found a nice one for less than $20