I raise a lot of citrus, one of my primary hobbies. Sandy soil with large grains doesn't hold moisture so unless it has some other soil (clay, silt, etc) as a subsoil layer within 12", you will need to frequently water. Daily to thoroughly wet the root zone for first four to six months, then 3 times a week (unless it rains). Mulch a radius of 3 feet at least 6 inches deep all around the tree to help hold moisture.
You could add soil amendments such as compost, peat moss, moisture absorbant crystals (like used in diapers) & sold at garden centers, or vermiculite. All will help give it a better chance of survival.
Buy a tree with the largest container you can afford, cut the top back 1/3 at transplant to help the root zone establish whil supporting a smaller top.
Good luck,
Louis