Photoshop Help Question

[Indifferent Clox]

Ok my friend needs help with some Photoshop stuff here is what she asked me:
I can't unlock this one layer. and it's not letting me make a new one.

I've tried everything I can think of

including saving it in a different format
renaming the layer dosn't work
nothing works


I'm not used to PC photoshop either


I'm working on graduation invitations

I need to adjust the opacity of the bacakground image so that it can look kind of like a watermark and I can have the text over it but I can't because the layer is locked.