In English counting "zero" values requires pluralization. Sometimes "no" means "zero", sometimes it is used as negation.
Counting is almost always valid, and negation is almost always valid, the one you choose to use depends on your intent and the context. Negation always preserves the plurality of the original statement.
If there is a question or implied question, it is usually best to use negation, which will never change the plurality of the question. For example, for the following statement:
You need a friend to enter.
A possible answer is:
I have no friend with me.
This is only because the question was singular and you are intended to negate it. If you responded with "I have no friends with me", it would be awkward, as it would mean you both pluralized and negated the original statement, where you should have only negated it.
Often times due to the ambiguity the use of "no" for "zero" is avoided, and can come across as a mistake. It is sometimes also used to emphasize certain words.
It will come across as more clear if you work around "no" for negation, such as:
I do not have a friend with me.
This makes it clear you want to negate the "friend with me" clause, instead of trying to count how many friends you have with you.