So we're new to fish and have acquired a 56 litre (16 US Gal) Hexagon tank.

So I set it up and left it to cycle for about 10 days.
Before we stocked it we had the water tested and it was fine, 0% Amm, 0% Nitrite.
We purchased 2 pearlscales and within 10 days both were dead.

I now know this was due to massive levels of nitrite.
Amm's been fine through out, but Nitrite levels shot up.

After the first fish died I was doing alternate day 25% changes, but this didn't help.
Now as there are no fish, but some waste, would it be best to leave the tank "as is" and allow the bacteria to reduce the nitrite levels, or continue with the water changes ?

Any help would be great as we're completely new to this.

You need your tank to cycle out. Leave the tank running without fish and continue checking your levels.

Do I need to continue with the water changes, or would it be better to leave it as is for now, while checking the levels ?

Do not change the water leave it and continue testing till you are at thedesired levels

Right then, update.
I left the tank to cycle and have now got Zero Nitrate and Nitrite.
I have added a couple of fish.
So do I need to do regular water changes and if so what volumes ?