You'll be fine.
Since it's reporting the disk as 1.9GB it's clearly going to initialize the partition and not the entire drive. In addition, you can't initialize the partition you booted from.
Also, you can format it as HFS+ regardless of the partition type used on other partitions on the drive. You can have any mix of HFS, HFS+, UFS, etc. partitions on the same drive and you won't have problems.