Some Seagate drives come pre-formatted as NTFS. Macs can read NTFS drives as standard but as standard cannot write to NTFS drives. To 'solve' this Seagate has in the past done a deal with Paragon to include a 'free' copy of Paragon's NTFS software which lets Macs also write to NTFS disks.
It is possible to erase and format the drive in other formats, however in most cases the same issue applies in a different form. For example you could format it as Mac OS Extended aka HFS+ but then Windows would have a problem using it. You could format it as FAT but this does not support file sizes bigger than 4GB which these days is not exceptional. You could format it as ExFAT, both Mac and Windows can read and write to ExFAT but Linux as standard cannot. Also there are sometimes other compatibility issues with ExFAT but actually it is widely used for camera memory sticks these days. ExFAT does support file sizes bigger than 4GB.
If you do end up using the Paragon software you need a new enough version to support the version of Mac operating system you are using. It is possible the version included with a Seagate drive might be out of date and hence not support Mojave.
(Yes you could have both an NTFS and HFS+ partition but the Mac would only be able to access the HFS+ and Windows only the NTFS one. The Mac cannot format as NTFS but could create a FAT one which in Windows you could erase and convert to NTFS.)