What kind of veg is good to grow in greenhouse.

French beans perhaps?

Or maybe put in some overwintering autumn carrots or cabbages?

You can sow some lettuces for overwintering later on in the season too.

You'd probably get a crop of late French beans as you are in Ireland aren't you? I think some of the most underrated autumn and winter crops are Chinese greens like mizuna greens and mibuna greens, which you 'cut and come again'. Sow them quite thickly in the greenhouse bed.
There are also the winter radish, like black radish, which are more like turnips than salad radishes, but baby white turnips would also be a good option now. You could also get a crop of baby beet. I think 'Chioggia' are especially good for flavour and appearance (white with pink stripes).