。
Let's try something.
Literal
Something [omitted object-を] do-try [volitional-ましょう].
A textbook example of stacking ~てみる ('try doing X') with the polite volitional ~ましょう ('let's X'). 何か functions as the indefinite object, but the object particle を is dropped — common with 何か/誰か in casual or semi-casual speech. してみる literally is 'do and see,' i.e. 'try doing.'