Hi Peggy,
Great to hear from you and sorry for the trouble. If there is a /Users/<username>/xraylarch folder that did get created,
does opening a Terminal and typing
~/xraylarch/bin/larch -m
work (I think you are saying that this reports "..no such file or directory: ...").
If that is the case, maybe the installation did not finish correctly. If you are up for trying a few more things at the command line,
you might try
~/xraylarch/bin/python -m pip install xraylarch
which might work or at least give some useful error messages.
Cheers,