Hi @leahperl! Thanks for this question. To copy the shape(s) you’ve lassoed (and access similar options), simply press and hold the shape until a pop-up menu appears. This, rather than a single tap or selection, will act like a “right click”.
In case it’s helpful, I also recommend our Use Lucidspark on the iOS mobile app article from our help center - it contains additional tips on how use features specifically on mobile. I noticed you said you’re using the browser on iPad rather than the app, but the instructions should generally be the same!