Is it normal for a spur turtles shell to go soft?..if not what do I do to keep them healthy and how much food does a spur turtle need a day?(what kinds of vegetables)
There are at least two types of spur thighed tortoises. Neither should have a soft shell. You probably need better lighting (uvb) and calcium. A vet will tell you if you need something else as well.
The Mediterranean spur thigh will browse happily outside, and will eat flowers (hibisucs, rose, and nasturtiums are favorites) and will grasses and weeds. Grows to about 6-8 inches.
The sulcata is also a spur thighed tortoise. It will want to eat grass, hay (low in protein), weeds, cactus, a little fruit, and some vegetables. Grows to about 30 inches.