This depends a lot on your climate, and if it will be all the time, or just when the weather is good.
They need to be able to regulate temps, so heated hide, deep shade, plenty to graze on, and fresh water. You need secure borders that keep the tortoise in, and any predators in your area out.
You need a secure enclosure. Solid sides, not wire.
Some or all the enclosure needs to be in full sun so your tort can bask. An area of turf with weeds like clover and dandelion will be enjoyed for grazing. Some bare earth for digging in under plants. Some blue slate chips to create a hotspot.
As well as a proper shelter, your tort will appreciate shelter from plants and shrubs. Check out The Tortoise Table Plant Database before spending money on new plants.