I have some other ideas on how to get started without using too much muscle - a broad fork or digging fork will take a lot of energy and time. Especially as grass with roots will be in the first 2-4 inches at least. My friend is making 50ft rows with his broad fork and I'm sure he could say that he's taking a beating making his beds. He's got the help from his sons too. No doubt it will be worth it in the end! After broad forking put some soil on top to begin the process of turning the space into an abundant garden. The grass will grow back if not turned upside down, removed, or covered until it dies and or compost. You may want to put a clear or black plastic on the grass patch for a few weeks before you start your broadforking/digging fork. This will help make the forking more manageable than live grass with good live roots.
This other idea will take less digging in the ground but you'll need cardboard, mulch, and compost or top soil. Plus lug the stuff onto your new to be garden patch. If you can source cardboard, layer the stuff thick on the grass, and make sure they overlap. The grass will search for a way through the cardboard and start growing through. If this happens, at least you'll have less grass to deal with than before. After the carboard layer, put a layer of mulch on top. This mulch can be spread wide, where you plan to have walking paths in the garden. This should still be a thick layer, and eventually will compost into the garden soil. Then put your planting soil on top of the mulch. Start planting into the soil. Much less digging, but will still take some muscle.
Instead of you making the garden - make chickens or pigs work for you. If you have experience and are planning on having animals or can procure animals from a nearby farm or friend for a little while, make them start the garden for you.
Justin Rhodes will put his chickens in an enclosed pasture with removable stakes and an electric fence. Leave the chickens there until the ground is down to the soil. Move them, and prepare the space for planting! Bonus if you throw food that has seeds and can easily germinate like; tomatoes, pumpkin, squashes (gourds with viable seeds inside of all types). This garden can look wild if you just let those grow, but instead you can harness what the chickens did and start your garden thereafter.
You can do the same with pigs. They will root up the ground for grubs and roots, and the ground will eventually be perfect for a garden. One pig can make a good size garden plot within 2 weeks. You'll need a good amount of chickens to do that, at least 20 within the same space. Pigs eat everything of course, and both pig and chicken manure will be great for your garden as long as you're feeding whole foods and non-processed. The chickens and or pig can help start the rest of your land as you move the animals to new spaces, turning the grass into abundance of food in the process, with less human muscle doing so.
Matter of fact, looks like Justin released a video that uses both chickens and pigs making his garden in two weeks. The animals can work together like in the video or in succession.