I have seen on the chemistry answers that a symbol is used please can you tell me what it means they are the upside v

Question

eg Na^ and CN^

It means that the number or symbol that follows is placed in the top corner of Symbol before it

E.g cm^3 or CN^-

you just cant write them on here

so what does H^+ mean?

The ^ is a caret. It means that the following typed "whatever" is a superscript. We can't write superscripts (without a lot of trouble). Neither can we write subscripts without a lot of trouble, which is why we write H2O instead of H₂O.
For example, H^+ means H⁺ which is hydrogen ion. And (H^+) means (H⁺) and that means "concentration of hydrogen ion."

Na^+ means sodium ion and CN^- means cyanide ion. They should be written as Na⁺ and CN^- but the ^ is an easier way to do it.

ok, thanks