Hi Danielle, I'm not too sure how strict the m.o.t. is in Britain but the lights, mirrors & speedo would be a definite fail if it was a car.
You can buy replacement mirrors in any good bike shop & they just screw into the handlebars. The speedo cable is probably broken so you might have to order that in. It's a tricky enough to fix if you have no mechanical experience as the cowling around the handlebars & the front light panel have to come off in order to route the new cable.
Does the starting motor work? The reason i ask is because of the electrics. There is something drawing power away from your lights, may only be a loose connection or a bad earth but start with the battery & see if it's any good.
steo
June 2009