When I right click a cell I usally want to copy its contents.

But the menu I get the first time copy is not a clickable option. Second time I right click the cell it is clickable. Can you change that?

Not clear to me what you mean. Right clicking provides a context menu showing Copy (CTRL-C) and if your question is meant as a request to developers, this site is not the right place to address enhancement / change requests (Go to Bugzilla for this purpose).
If you want to clarify your question, please edit your original question and add further details (please don’t forget to mention your operating system and your LibreOffice version).

If still the context menu of a different object (cell, sheet, range …) is open, the first rightclick will close it. You then need a second mouse action to seclect a next cell. This is unchanged intended behaviour for all LibreOffice releases since the first one (V3.3) published under this name.

If not such a context menu is open, I get at the same time a next cell selected and its context menu (including an enabled an working ‘Copy’) opened if I rightclick into the area of that cell. This also is unchanged since the mentioned version and up to my present version under testing which is V6.3.0.2RC.

Please try anew, and if the behaviour you described (‘Copy’ disabled or missing or enabled but not working?) is a fact, you may carefully try a reset user profile. Read this page completely first.

Thank you very mutch Lupp!
I copied all to a new file and voila