Well you have to have a UV Light, a Turtle Dock, a Filter, a Heater, and at the least a 10 gallon tank. You need 1 gallon per inch of turtle. I have two baby painted turtles and they eat "Baby Shrimp and Krill" and eat alot each day. You should get some plants and gravel to put in the tank too. Turtles love to swim, so in the summer you can build a little pond and let the turtle live there until late autumn. You need to leave the UV light on at least 6 hours a day.
Keep it away from water that's too deep and do what you normally would do to care for your turtle.
Painted turtles need water and a place to bask. They need to have at least a twenty gallon tank.
http://www.reptilesmagazine.com/Care-Sheets/Turtles-Tortoises/Painted-Turtle/
land turtle
A aquatic turtle because of it's special needs. A turtle is easier.
How Long you can keep a Turtle as a petWell, it depends on the turtle type. And how you take care of it. Most tortises can live for almost 160 years. But turtles, not as much. If you take care of it properly, then it will live longer. But if at some time you don't want, or can't take care of it then you would have kept them, what ever months or years, or maybe even weeks. That's all I can try to answer for your Q, glad to help! :)
Like any other turtles. Make sure that you have a big enough habitat for him/her. Make are there is enough water in the habitat (at least 1 inch above their shell because turtle can drown.) Have a proper basking area such as a rock, and have a heating light above the basking area.
what environment should i keep my IT turtle
You don't. That's like saying "How do you feed a human with only water?" A turtle needs UVB and UVA light no matter what, they can't live without it. It is what allows them their shell to grow. If they don't have UVB or UVA light, their body will grow until their shell can't take it anymore and 'pop', dead turtle.
who painted the london bridge??i dont realy know and i dont care
Almost all reptiles just lay eggs and leave the babies on their own. Alligators are one exception - they care for their young for awhile.
by putting them in its shell
It dosen't
I believe it is turtle
there are a lot of good websites that give helpful information about what a turtle eats. It would probably be helpful if you knew what kind of turtle you had. Then just Google care for your pet turtle, or something like that.