Just to add my 2-cents, and confirm what others have said above:
Okay, there are various partitions on an Amiga hard drive, DH0:, DH1:, etc. as you've been told. DH0: is USUALLY the bootable partition on the hard drive that contains the operating system (called "Workbench"). Usually, it is the practice of Amigans to keep this partition relatively small and put the Operating System on here (along with its related files like fonts, device drivers, libraries, etc.).
USUALLY the applications and other programs are kept on another partition, often called DH1:, DH2:, etc.
Note that while these drives are assigned the names DH0:, DH1: etc, the icons for these drives can be given different names (DH0's icon might say WORKBENCH or MAIN, DH1 might say APPS, PROGRAMS, or whatever the user wished).
If DH2: is for some unorthodox reason the OS/Workbench partition instead of a data partition then you will not be able to re-boot the Amiga into Workbench if you shut the computer off. In that case, you will be worse off than you are now.
I'm assuming the Amiga has been left on since you formatted the drive.
You mention that sometimes you get error messages saying that a file cannot be found....a few more details about what you are clicking to make this error message occur would be helpful. I'm guessing that this is because you've wiped certain files from DH2:
I am VERY concerned, that since you started formatting DH2: and then aborted it part way through, you have corrupted the drive quite a bit.
What you have ahead is a very steep learning curve. Especially if you have to restore or re-install the directory of the boot partition. I would REALLY suggest you find an experienced Amigan who can help you. Perhaps a friend of the deceased man who set up the system? You will save yourself a lot of grief this way. Rabbi posted above in this thread an offer to stop by and have a look....it would be a very smart to wait for this person. I know there are other Amigans in New York State on Amiga.org.
I am located in Eastern Ontario. I suppose in a pinch I could guide you over the phone.....but you have quite a restoration job to do there.....and it would be a very frustrating thing to do over the phone without visuals and without you really knowing much about what you are looking at (not having detailed knowledge of the Amiga system).
Also, you should be aware that there is an icon called CLI: or SHELL in the SYSTEM drawer on the Workbench partition. That will get you into a MS-DOS like interface. It might be better for you to use that type of interface....it's more straightforward for low level restoration like this.
