my garden is so full of rubble, rocks stones

Hi Cal67! We live on a mountain in Spain so our earth is loaded with mainly limestone stones, rocks and boulders. My partner built a barbecue base with the more suitable rocks - that got rid of some of them, but others are trundled away by our neighbour's small tractor to who-knows-where. We have a stacks of flat rocks which we will use to make pathways, once all the major digging is finished. Hope this helps.

At one time I had a lot of rubble to get rid of. I decided where my paths etc were going to be and dug out all the useable top soil from this area then back filled the trench with the rubble and built the path on top.

Your other alternative is to make a featue of the conditions and plant a garden of exotic looking desert plants which are hardy enough to cope with our weather. Phormius and astelias, sedum spectabile and other plants with succulent leaves, lavender and rosemary, cistus and bearded iris - these will all appreciate your conditions especially in a sunny spot.
You don't say where in the UK you are but if you're anywhere near Norwich, visit East Ruston Vicarage garden where they have made a desert garden to get some more ideas

It also depends on what the material is. Building rubble always looks like building rubble, so best bagged and taken to your Council Recycling area. They usually have skips for rubble like that. If the stones and rocks are 'natural' material then there are lots of freatures which can be made from them, as suugested.
We have removed over 30 tons of rubbish from this garden over the last 14 years, but we have also found huge numbers of glacial erratic 'beach type' stones. These we have used to create screes, rock gardens, gravel gardens, dried up river beds and dry stone walls around the garden.

Build a stone wall with the good looking stones on the outside and the rubble inside and as you build keep adding plants such as sempervivums, campanulas, lewisias, saxifrages you name it!