Thanks for the info - I am gathering expertise as I go along.
The lady who lived here before us was a brilliant gardener and it is stuffed with wonderful things - we decided we would wait a year before doing anything major, just to see what comes up. The only thing we have done is to replace a vegetable garden with a scented garden, as we knew we would not have the ability to grow vegetables. And we had a new patio made with a little low wall round it, which we filled with scented herbs - it overlooks the new scented garden which has scented roses, mock orange and lilac in it - can't wait for the summer!