Flattening out of garden, and putting stones and terrace planks on the ground

We are looking into work in our garden. i enclose some photos, We would like to extend the area of the garden and flatten out the ground. If you look at pics you will see the stone wall, we want to remove this and flatten that area all the way to the garage, so that we end up with a larger flat area. On one of the picture, you will see that we need to remove the terrace floor at the bottom, here we want to put new flooring down. We would also like an estimate for extending the terrace on the top floor, here we would like to extend the terrace in a area of 15m2. Note: photos missing.