The computer that I have been using for other Zoom sessions defaults to identifying me as just Richard. I think it's possible to change that from within the Zoom application, but maybe not in advance.

Also I ought to mention that my local club, Herga, normally meets on Monday evenings (though I attend very seldom) and is currently having Zoom sessions; but there are probably several such sessions every day somewhere or other, so not to worry about clashing with someone.