Нам нечего скрывать.

English Translation

We have nothing to hide.

Should be ничего; нечего means “something”

Actually, I think this sentence is correct. From Wiktionary:

there is nothing to (negative genitive of что (što))

мне не́чего де́лать
mne néčevo délatʹ ― there is nothing for me to do.

If you do an Internet search for “ничего нечего difference”, you’ll get more information.