DVD Recorder?

I have a new Sony DVD recorder RDR-HXD790. I tried recording to a disc and now cannot get back into the Programme Guide it says Function not available, display on the DVD screen says L2. When TV on a cannot record any programmes and screen in LH corner says AV2. All worked perfectly before trying to record the DVD. I am a pensioner and a novice with these devices, I have probably pressed the wrong button, Help please. Many thanks