How can copy a file from my virtual machine to my host machine ?
Thank you in advance for any answer.
What are you using to virtualize the virtual machine?
I think f.e. Virtualbox have a drag'n'drop feature that can be installed. I also belive some virtual machines HDD can be directly accessed with no fuss.
If that seems complicated another option is to simply transfer the files using the emultated network(I think most basic emulators use NAT between the host and the virtual machine) so you could just use a filetransfering program. I prefered(when using windows) to have bitwiseSSH to communicate with my linux machines(assuming it is that way) then you could just set up and SSH to allow transfer and you should be able to access all files that user is allowed to access.
You will have to install the guest add-ons to allow for copying files between the VM and the host if you are using Virtualbox. Or, you can just send yourself an email :-). What VM hypervisor are you using.