Lock screen cant be customised

[Mememaker2]

I have Windows 10 home and when I go to customise the lock screen all it says is "some settings are managed by your organisation"

 

[RecumbentTim]

Try this, Search "Customize Lock Screen" from the search window on your task bar. Pick an appropriate offering. I used "How to Geek.com".

 

[Trouble]

I have Windows 10 home and when I go to customise the lock screen all it says is "some settings are managed by your organisation"

That sounds like a message you would receive if you had used the Registry or Group Policy to disable the lock screen.
Since you have the home version which doesn't contain the Group Policy editor, I would suspect a registry edit is at fault.
Perhaps check here in the Windows Registry
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Personalization

If the key exists and you see a value in the right pane "NoLockScreen" with a value of "1" then you might want to edit it and change it to "0"

Using the Windows Registry Editor can cause serious, system-wide problems that may require you to re-install Windows to correct them. It cannot be guaranteed that any problems resulting from the use of the Windows Registry Editor can be solved. If you choose to edit the Windows Registry please understand that you do so at your own risk so unless you feel fairly comfortable and confident you should probably not use the Editor. Changes made to the Windows Registry can take effect immediately and those that do not will take effect following the next reboot of your computer, and a current backup is not automatically made for you....So manually create a system restore point, backup the registry and export the key you are editing for safe keeping before doing so.