Ok, I have an IBM SCSI drive so first solution is not good .... my Mac have an old 40MB Quantum drive and when I want to work(play) with it I need to rotate the "disk" with the finger (like oldest cars), then close the box (of the disk) and "work/play" with my second Mac (my first one was a Classic and I was so young and stupid to open it with an hammer ). Now someone can help me to find a solution to use a IBM scsi disk (year 1997)?
Plug it in and try it out. Here are a couple of resources to help you figure out how to format your new drive:
The tricky part will be getting code from the Internet onto your Mac SE. Do you have another Mac that can create floppy disks that the SE can read?
I've been able to use several SCSI 1 drives on my classic Macs. You should be able to reformat any drive with the System, Apple's drive setup tools, or third part programs if you have any. I've used anubis drive tools on my old hard drives on my Plus and SE and I swear it could even resurrect old harddrives and make them usable for my old Macs.
The easiest thing may be to get an Apple Utilities / Tools floppy image from Apple, then write it to a floppy using something that can write floppy images. After you do that you should be able to boot from it and format your new hard drive.
As far as downloading things off the internet, if you have Ethernet in your Mac it make things easier. You can then use a web browser or a tool to save files from a URL.