Ok so I have downloaded a Windows 10 iso onto my phone and I think that i could use my phone as a bootable device. Is there any way I can make my phone a bootable device? I need to reinstall Windows onto my dell inspirion 14 laptop.
It would help to actually specify what kind of phone you have, but the answer is, probably not -- and even if you could, just having an ISO file on the phone won't make the phone a bootable device. ISOs need to be burned to disc in a particular way or extracted onto flash drives with some extra prep steps in order for the result to be bootable. Just grab a flash drive you can afford to erase and then get the Rufus application (available at rufus.akeo.ie) to make a bootable flash drive out of that ISO.
I have a galaxy note 5. And I don't have any way to use Rufus. My laptop won't work that a why I'm trying to reinstall Windows 10. And I have no other computers at my house
If you don't have any other PC, then you're very likely stuck. Even if your phone did work, you'd have to extract the contents of the ISO onto the virtual flash drive that your phone would present to the PC and probably set that virtual flash drive partition as "active" (bootable) if your Inspiron 14 doesn't support UEFI booting. Or I suppose you could have the phone emulate a DVD drive with that ISO specified as the inserted disc, but I'd be surprised if even Android had apps that did either of these things natively on the phone.
Realistically, whenever you can get to another PC, just have a blank DVD or flash drive handy, then use Microsoft's Media Creation Tool to get yourself set up. It's not the most capable or fastest tool out there, but it's easy.