Googled and found them. They are not a product I'm familiar with.
I should warn you that test strips are considered to be quite inaccurate. And they don't include ammonia - Sera's website
here shows the strips test for pH, KH, GH, NO
3 and NO
2 - that's pH, carbonate hardness, general gardness, nitrate and nitrite. You need an ammonia test asap as that's the one that rises first, and you need to know the level urgently.
Can I suggest you get an ammonia test as soon as the shops open in the morning, preferably one that has bottles of reagents. You can buy tests singly, but a kit containing ammonia, nitrite, nitrate and pH works out cheaper than buying them all individually. On-line is cheaper than real shops, but you can't afford to wait for the post for the ammonia tester.
You got six fish yesterday. Since you can't test for ammonia, the safest thing would be a 50% water change this evening - just remove the water with a jug or something, it'll be quicker and there won't be much mess in the gravel yet. Then when you've got your ammonia tester tommorrow you can check the reading and see if you need another water change.
As for the strips, according to the instruction, you dip the strip in the water for 1 sec, shake off the excess water and wait 60 secs. Use a kitchen timer if you have one. Then hold the strip to the chart on the side of the pack, preferably in daylight. Each test should show a range of colours. One by one match the individual test patch to it's corresponding shade card and make a note of the colour that is closest to your strip.
I don't like the idea of putting a strip containing chemicals into a fish tank. I would use a tub to remove a bit of water then do the test over the sink. And as for the daylight bit - with liquid testers, energy saving and other fluorescent tubes can make the colours look wrong. Halogen bulbs and old fashioned bulbs are OK. I haven't checked them under led lights yet so I don't know about them.
The results - pH could be anywhere between 6 and 8 depending on your water supply. KH and GH could also be anything from 0 upwards; don't worry about them at this point. Nitrate will probably show some reading between 0 and 50. It is unusual for it to be zero, and 50 is the upper limit allowed by law. Nitrite should be zero at this point. You don't have any ammonia eating bacteria yet and they make nitrite. No bacteria = no nitrite.
But you will probably have some ammonia, only the strips don't test for it. You need to know your ammonia reading so you know when to do a water change. I know I'm nagging, but get an ammonia test!!!!!