If I understand your information, you wish to raise the structure and install a wooden floor supported by joists over pier blocks. Based on your picture and location it appears that you are in a moist area and need to consider that when you remodel the floor. A raised floor on piers will provide an air space under the floor and help keep it dry. Any wood under the structure may need to be pressure treated to avoid rot and mildew or fungus.
If possible, you may be able to raise the shed and use peeler cores from the Home Depot and roll the shed out of the way while the proper floor is built. Afterwards, the shed must be placed on the new floor and trimmed out to be weather proof. Not an impossible project but one requiring some planning to accomplish. Best wishes!