Is it a liquid test or a dip stick? I'd recommend getting a nitrite, and nitrate test as well. 
In a 10 gallon, you are pretty darn limited when it comes to "larger" fish, unfortunately, to basically, nothing. Any fish larger than 2-3" will be stressed in such a small tank, stress compromises their immune system, which results in sick fish. This is why 10's are left best as quarantine tanks, or for "micro" fish, inverts-shrimps, dwarf crays, african dwarf frogs, bettas, and a few others.
Haha yay I'm psychic!
(I personally try to avoid petco/petsmart, as they treat their animals like crap (some actually treat their fish really well, but the rodents, birds, and other animals are treated badly, crammed in cages together in the back, and often come from disgusting puppy mill-like places. I get my fish from craigslist now, not supporting any companies I don't like, and don't have to worry so much about quarantine. I will buy frozen food from them though, as it's the only place around that carries frozen bloodworms regularly and is sadly better than some of the local "pet stores" around me.)
Back on topic though,here's a link for some stocking ideas, I'd type em up but my comp's gonna die soon. http://www.badmanstropicalfish.com/articles/article63.html
I'd *highly highly highly* recommend getting more decor. 1 cave, 1 plant is just not enough cover for fish to feel safe. Something like this would be great!http://www.petsmart.com/product/index.jsp?productId=10933771&f=PAD%2FpsNotAvailInUS%2FNo http://www.petsmart.com/product/index.jsp?productId=10930584&f=PAD/psNotAvailInUS/No and silk plants are important for fish with long fins such as guppies or a male betta :http://www.petsmart.com/product/index.jsp?productId=10933767&f=PAD/psNotAvailInUS/No
No need to feel bad about being new to fish world, we all started somewhere!
In a 10 gallon, you are pretty darn limited when it comes to "larger" fish, unfortunately, to basically, nothing. Any fish larger than 2-3" will be stressed in such a small tank, stress compromises their immune system, which results in sick fish. This is why 10's are left best as quarantine tanks, or for "micro" fish, inverts-shrimps, dwarf crays, african dwarf frogs, bettas, and a few others.
Haha yay I'm psychic!
(I personally try to avoid petco/petsmart, as they treat their animals like crap (some actually treat their fish really well, but the rodents, birds, and other animals are treated badly, crammed in cages together in the back, and often come from disgusting puppy mill-like places. I get my fish from craigslist now, not supporting any companies I don't like, and don't have to worry so much about quarantine. I will buy frozen food from them though, as it's the only place around that carries frozen bloodworms regularly and is sadly better than some of the local "pet stores" around me.)Back on topic though,here's a link for some stocking ideas, I'd type em up but my comp's gonna die soon. http://www.badmanstropicalfish.com/articles/article63.html
I'd *highly highly highly* recommend getting more decor. 1 cave, 1 plant is just not enough cover for fish to feel safe. Something like this would be great!http://www.petsmart.com/product/index.jsp?productId=10933771&f=PAD%2FpsNotAvailInUS%2FNo http://www.petsmart.com/product/index.jsp?productId=10930584&f=PAD/psNotAvailInUS/No and silk plants are important for fish with long fins such as guppies or a male betta :http://www.petsmart.com/product/index.jsp?productId=10933767&f=PAD/psNotAvailInUS/No
No need to feel bad about being new to fish world, we all started somewhere!
