Ubuntu can read NTFS file systems and drives formatted by other OSes, such
as Windows. To format in Ubuntu you use a partition editor such as Gparted.
I do not use Ubuntu, but Kubuntu, and can't tell you where to find the
partition editor precisely, but look under System, Administration.

If you want to access the external drive in Windows then use a Windows
format such as NTFS. If you want to use it just in Ubuntu then a Linux file
system is better because it does not need to be defragmented. You can format
NTFS or ext4 from the partition editor in Ubuntu.