I would recommend against Wubi, just use the normal installation ISO image and either dual-boot or use a VM such as VirtualBox (which is nice for starting with Linux, since it doesn't reisk your data and you don't have to leave one OS to use another).
Also, LibreOffice works in Windows. You don't need Linux for it (although you really should still try Linux, you might even like it better than Windows and decide to switch!
)