Not sure if anything is actually needed. It just looks unstable. Power is already run to the shed, so it might be difficult to move and do a full concrete pour. I was thinking of lifting with a car jack and finding a better combination of pavers to remove the wood wedges, but I'm open to any ideas. And it is on a slope, the other end is on pavers on the ground. This stack of pavers was the previous owners attempt at levelling I guess.
Not sure if its the best way but Essential Craftsman has a video where he fixes the foundation of a shed like yours. https://youtu.be/PUNKHpVBbGk?t=72 Essentially he uses a jack to raise up parts of the shed and uses lumber to temporarily support the shed while he pours gravel under the foundation. Then using a jack or lumber to create a lever to raises the shed again and put it back on the masonry blocks.