Hi Barney
I have to tell you that a 10 litre tank is not suitable for any fish. You might get away with keeping shrimps in it but that's about all. Please ignore all those comments on Amazon. This size is not suitable for neon tetras, white clouds etc and certainly not for goldfish.
If you went for something a bit bigger you would be able to keep a siamese fighting fish, usually known by the name betta these days. The minimum for a betta is 5 American gallons, which is 19 litres.
But small tanks are harder to maintain and don't give you much choice in fish. If you could accommodate something with a footprint of 60 x 30cm you'd have much more choice. The 50 litre tank in my signature is this size, though it is a shallow tank. Taller tanks would give you something like 60 litres. And even bigger would give you a lot more choice.
If a larger tank like this costs a bit too much for a first tank (you may decide fish keeping isn't for you after all) look at second hand tanks on Ebay, freecycle, facebook groups etc.
You will need a tank with a filter, heater and lights. There are few cold water fish suitable for small tanks, most small fish are tropical which is why you need a heater.
Something your family may not have known about when you were a child is cycling a tank. This is the name given to the process of growing bacteria in the tank which 'eat' the toxic waste made by the fish.
Before you go any further, can I suggest you read these:
Cycling without fishCycling with fishCycling without fish is easier because if you make mistakes you don't kill any fish.