The idiomatic expression "first dip" means to take the first step or action towards something. It can also refer to a person's initial attempt at doing something, such as trying out a new hobby or skill for the first time.
, but it is the company's first dip into the cash back pool. (thesimpledollar.com)
I am glad at least one of us will wear them... and remember, first dips on any kind of shoe swap. (agirlinboston.com)
I felt fascinated by all its changing colours and moods and I would imagine first dipping my toe into it and then swimming in the waves. (breastfeedingtoday-llli.org)