Hi Tori.
My first suggestion to to do some research on the different turtles that are available and see which ones interest you. Turtles come in a wide variety of sizes, personalities, and needs. If you are looking for some basic aquatic turtles, I have some suggestions for you.
Because you a beginner caring for turtles, I would lean towards some of the more hardy turtles such as a red earred slider, map, cooter, or painted. All of these turtles are relatively easy to find and inexpensive ranging from $10-$30. As juveniles, each of these turtles can be housed in a 10gal aquarium with a basking area, UVB lighting, and a heat lamp. Also, it is very important to have a good filtration system either submersible or canister filters. Stores do sell 10gal aquariums designed for turtles. A slot has been cut out of the side so canister filter can be used. As they grow, a larger tank will be needed. You can find a lot of information on aquarium setups for juvenile turtles online.
I personally would lean toward a cooter. They are the most tame turtle of the bunch. The one I have at home has no problem being held and actually likes being pet. On the other hand, my red earred slider, map, and painted prefer to be left alone. Keep in mind that the cooter iss the largest turtle of the ones listed and can grow to be 9''-13''.
Good Luck.
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Mike
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2 Painted
1 Musk
1 Common Snapper
1 Cooter
1 Map
1 RES
1 Corn Snake
1.1 Water Dragons
2 African Frogs
1 Toad
1.0 Degu
1.2 Chihuahuas
0.1 Cat