Grazing

I have a Leo Tort hatchling and I want to take him out to a grassy area (no pesticides) to walk around, get sunlight and do his tortoise thing. But I worry he will eat something he shouldn't. I'd like to think that when they are in the wild, there isn't someone monitoring what they are and aren't eating and instinct tells them whats ok and not ok to eat. Am I correct in thinking he will know what's OK and whats not? There are so many types of weeds out there and I'm trying to learn what's safe and not but that could take awhile and isn't fool proof.

He won't know whats poisonous. A tortoise will eat tulips, that causes swelling around the eyes as well as other problems. You could download a plant identification app like PictureThis, or maybe just watch him closely.

I don’t have a leopard tortoise, but I have a sulcata. They will eat just about anything. I would learn what weeds you have and go from there.
You can take some pics of the weeds and post them in the plant Id section of the tortoise diet forum.
If you keep a really close eye on him, I don’t see the harm in taking him out to get some sun