In which sentence is the word camping a gerund?

My family and I enjoy camping.

We noticed the camping club had set up their tents nearby.

Last summer, we were camping at the base of a waterfall.

my family and enjoy camping

My family and I enjoy camping.

Explanation:

A gerund is a verbal formed with the root of a verb + - ing (like "camping") that does not act as a verb but as a noun in a sentence, thus, it can be a subject, an object of a preposition, a direct or indirect object or a complement.

The word "camping" acts as a gerund in the sentence "My family and I enjoy camping" because in here "camping" is not a verb, but a direct object, that is, the recipient of the verb "enjoy."

In sentence 2, on the other hand, "camping" is an adjective that describes the noun "club" and in sentence 3, it is part of the verbal phrase which indicates the past continuous tense.