If the phone is locked and i buy extra storage for iCloud would it still backup all my pitcures ?

If you mean just locked with a passcode/Touch ID/Face ID and your iPhone is connected to the internet then in theory it should but make sure you plug it in. This is because iPhone doesn't upload stuff to iCloud constantly when on battery power, this is to prevent battery drain.

If the phone is disabled and you cannot enter your passcode because you did it wrong too many times I am not too sure about that, you may have to contact Apple Support.