White smoke is probably oil. The initial hit could have been from oil somehow getting into the combustion chamber while it out of the car. Being moved or stored at the wrong angles or just something that some used to clean the intake with so I wouldn't worry too much about the initial startup smoke. If it carries on though there could possibly be issues. Maybe rings or valve seals. I had an old Vectra that had leaking valve seals and it would smoke a bit every time I started the car for about 10 seconds and that was about it.