different kinds of hash verifications, and writing boot disk iso to USB

Fedora - the hash is in a file called NameofISO-CHECKSUM:

sha256sum -c *CHECKSUM

OpenSuse is similar - the hash is in a file called NameofISO.iso.sha256:

Ubuntu - has sha sums as well as  md5sums, so can use

md5sum -c MD5SUMS 

also.

Then, writing - for Ubuntu based distros, can use the "make startup disk" tool. If the iso is from a different distro, and it is known to be compatible with usb boot, then something like (after verifying the device name - sdd or whatever - very important!)

sudo umount /dev/sdd*

sudo dd if=Fedora-Workstation-Live-x86_64-24-1.2.iso of=/dev/sdd bs=8M status=progress oflag=direct

The above method is known to work for Fedora 24 to 29, and OpenSuse 13.2.

If it is a DVD iso and not meant for USB boot, maybe unetbootin is required.