External Hard Drive - Reformatting and General Access Questions

I purchased an external hard drive from a second hand store (Toshiba Canvio Connect 500 GB, USB), and I have a few questions on it:

Background: When I first plugged in an error popped up saying the USB drive needed repair, I clicked OK and it failed. I opened the properties and the disk space claimed 100% used. I tried scanning the disk for viruses and malware before I tried opening it and that also failed. Then I attempted to open the folder, it prompted "Access Denied". I clicked around in properties but wasn't authorized to change any settings. After about 10 minutes, it opened. I then tried the virus scan again and it worked, scanning the files I later found plus a bunch of %recycle bin% files that I couldn't find. Inside were videos for a project the prior owner had apparently been working on. I tried to delete these files, and it wouldn't let me. No option for it, and I got the red cross of "not happening" when I tried dragging to the recycle bin.

So, I right clicked the folder and selected format. I code"Restore Device Defaults" and "Quick Format," and it failed. I then tried unchecking quick format, and it started, but the process bar made no progress. I tried to cancel, and it wouldn't let me - my options were retry the cancel or press cancel to cancel abruptly. I canceled abruptly and the disk under my computer disappeared.

I unplugged and replugged the USB adapter, and a prompt saying I need to format came up. I clicked OK, tried Quick Format again with no success, and resorted to the full format (probably better anyway). It's been running for nearly 2 hours and isn't quite to 50% yet. It also says 465 GB capacity when the drive is rated at 500 GB.

My ultimate question - is this all normal? Should reformatting take this long? Are the accessibility problems a consequence of settings from the previous owner? Does it sound like the drive may be damaged? I'm not computer literate (I'm proud I got a far as I did on my own) and I have 7 days to return this if it was a bad buy. Please help clarify these issues!

Thanks for the advice. It's been running for 4 hours now and is almost at 75%. I'll let this finish and see what happens. Second hand only happened because I had store credit, so if this fails to correct the issues I'll buy new. Is the deceased capacity that's displayed (465 GB vs. 500 GB) a sign of an internal issue, or is that normal?

465 is normal; usable capacity is typically about 93% of stated capacity.

You can easily download the hard drive analysis tool from the drive manufacturer's web site. It will probably have a short test and a longer one. The drive should pass both tests. The long test will likely take an hour or more.

The format "finished" after over 5 hours, just to say that "Windows was unable to complete the format." Says it's likely due to connectivity of the hard drive or that the drive is Read-Only. I don't think it's read-only, and the icon in the my computer has disappeared a few times, which I thought was just a consequence of formatting - but I'm likely wrong. Anyway, thanks for all your help. I think I'm going to return it tomorrow afternoon and just buy a new one. That's a shame.

I got it to work! I used a walk through on command prompts to clean the disk, then went to the disk manager to the newly unpartitioned space and created a new simple volume with it. I tried it with the default NTFS and it failed again, but noticed another option while I went through for exFAT. I tried that option and it worked!

However, I have no idea what these actually mean. I see that exFAT is primarily for Flash Drives, will this impede the performance of my External Hard Drive?

What did I actually do here?