The problem may be with Windows, namely Secure Boot. I have a Dell, running originally Windows 8. I could never persuade it that Opensuse could use secure boot (as it can), even for installation on one of the machine's own drives, so I had to switch off secure boot (F12 gets you there) and install without it. During installation, put bootloader on the installation drive partition for / (/dev/sde1 or something like that). Now you have to use "Boot from USB" to start it, selecting the correct USB. Provided you only use Linux. it will be remembered at the next boot, but if you want to use Windows, you have to restore secure boot, then go through the whole rigmarole again for Linux. With Windows & there was an easier way, using Neogrub in Windows, but Microsoft prevented them from developing later versions.

these permissions have three numbers: the first is for the file's owner; the second for the group; and the last for everyone else. To calculate which number you should use, add 4, to give read permission, 2 for write, and 1 for execute. Thus 7 is all three. 6 is read and write, but no execute; five is read and execute, but no write; 4 is read only...

thus setting permissions to 775 or 755 seems more sensible on your home folder...

I am trying to partition the USB using Gparted prior to installing the Linux OS to it.

Unfortunately, under partition new and delete are greyed out. Also after creating a small partition Gparted will not allow designation of the remaining unallocated space? The USB is unmounted and formatted ext4.

Is the USB already formatted as a Windows partition? You may need to remove it in Windows.

I did finally give up trying to install the OS onto a USB. I could not get Gparted and the USB to work together as a beginner as hard as I tried. When the OS did seem to install it did not boot up.

Unfortunately, the attempt above left me with boot problems so I also had to reinstall the bootloader on one old netbook (with dual boot linux/windows HD ), using Supergrub2 - that worked very well.

Finally I have settled for a live USB with a largish persistence as this seems the easiest option if I do not want to install alongside windows and cannot install fully onto a usb easily. I will back up personal files in the meantime and at the time of upgrading swap my personal files over to any new OS I have then (if I can solve permissions as suggested above).

Thanks to those above for the guidance and it may help others trying the same. Having Linux as a Live USB is still good for me and a quick way out of windows whilst keeping it temporarily for occasional things.