Street View

A bit of street photography for U3A. Not a genre I'm comfortable with and I don't like to focus overmuch on passers by; but I do like this street art.  It brightens up a drug-ridden area of Boscombe.
Does anyone know how to deal with perspective in Photoshop Elements? It's not something I know much about, and if I straighten the horizontal the vertical goes out of kilter.