Option 1: Before booting up CentOs, go to CentOs VM settings, specify a share folder. Then after logged in to CentOs, create a new directory for example /media/vboxshared and mount that drive using the command sudo mount -t vboxsf SHARENAME /media/vboxshared. Enter your password when it prompts for the password.
Option 2: Before booting up CentOs, add a new Network adapter and select ‘Bridged Adapter’. Then after logged in to CentOs, run the command ifconfig -a | more to get the ip address of that new network adapter. In Windows Host, use WinSCP or FileZilla to transfer the file to CentOs