With the new file system in High Sierra (APFS), you have a physical partitioning and a synthesized partitioning. Partition 0 isn't really a partition per se, so for the physical partitioning you have 2 partitions - the EFI partition, which is normal and the APFS container.
For the synthesized partitioning, what you have is now the "new normal" when APFS is used.
So what you have is normal - you did nothing wrong.
Do you want to have another partition? If so, why do you want to have another partition? The question is not meant to pry or be perjorative, but now with APFS, if you want to add another partition, you can either have another physical partition or another synthesized partition. If you're looking to partition your disk for Boot Camp, Apple says to use Boot Camp Assistant. If you're just looking to add a second partition to separate your data, then Apple suggests you "Add a volume to an APFS container".
https://support.apple.com/guide/disk-utility/partition-a-physical-disk-dskutl14027/mac
If you look at your diskutil report, you'll notice that your Macintosh HD has only 34.1GB of space. That's because the containers in APFS can be dynamically sized.
Now there may be a reason to have another physical partition - which can be done in Disk Utility (I haven't ventured into that part of Disk Utility yet).
I'm presuming in all of this that your disk is the system/boot disk. If this is a second or external disk, then perhaps you would want to do something else - you'll need to provide more information.