How would I download a new copy of windows onto a new harddrive or ssd if I can’t access my computer
As
@Lafong says, that's where you need a friend/relative/local computer repair shop with another computer, to download and create a bootable USB memory stick with the Windows 10 installation files. It's a relatively simple process, once you've understood the concept.
The basic steps are as follows:
1). Go to the Microsoft web site and download the Windows 10 ISO file.
https://www.microsoft.com/en-us/software-download/windows10
2). Use Microsoft's Media Creation tool or a small program called Rufus, to "burn" the ISO file to a USB memory stick (8GB or larger).
3). Fit a new SSD in your computer. Disconnect all other drives.
4). Plug the USB memory stick into the back of the computer and switch on.
5). If the system doesn't detect and boot from USB, you may have to enter the BIOS and set the "boot order" to "USB first".
6). Follow the on screen instructions and install Windows 10 on the new SSD.
7). This can get quite involved, especially if you want to use a "Local Account" instead of a "Microsoft Account". There are numerous guides and videos on the web showing more detail.
is there a way to completely delete all files and data on a drive whether it’s new or old
As already mentioned by
@Lafong, there are ways to completely delete everything on the drive, but that assumes the drive is still fully working.
There are many different methods of wiping all data without trace, but check they write random data
over the entire surface of the drive, replacing old data with junk data. A simple quick format isn't enough. Files may still be recoverable using programs like Recuva.
If the drive is covered in "Pending Sectors" and/or "Bad Blocks", you may experience difficulty wiping it. A drive with these hard faults should be dumped/scrapped/binned/never used again, after file recovery.
If the drive has gone bad, one method of preventing file retrieval is to grind it into small pieces in a hard disk shredding machine. This is how some Government departments get rid of their drives. Another less sophisticated method is to hammer a 6 inch nail through the casing, or drill holes in it (take care). I prefer to remove the cover plate and whack the inside with a large hammer (wear safety goggles).
If the drive is still accessible when plugged into a computer, I'd probaby use a small program called Eraser. Or you could boot from DBAN (which I've not used). There are probably much better ways to wipe a disk.
https://eraser.heidi.ie/download/
https://dban.org/
Just make sure you've copied all the data that is still accessible over to your new SSD, before wiping the old drive.