am looking for a program where I can download Linux on my USB stick, but on the other hand I leave no traces on the foreign computer, it starts again as before after removing the stick.
To download Linux onto a USB stick SO THAT THE USB STICK WILL BE BOOTABLE ON ANOTHER PC.....you will need to use an app/program something like Rufus or Balena to ‘burn’ the iso file to the usb stick.
(It may be a good idea to verify the download etc.. you will likely find instructions on the download page for the Linux download)
When it has finished, take the USB stick out.
At this point you would need to uninstall the app/program you used (Rufus etc)...and also get rid of the history in the browser you used. Tails would not keep history but you would probably need to install tails in the first place and also uninstall it after you finish.
I have to ask you, Why?...does the foreign computer belong to someone who is “not Linux friendly”.....like your Dad ?