。
I saw him last week for the first time in a while.
Literal
I [topic-は] last-week a-while-since-[しばらくぶり][at-に] him [to-に] met.
~ぶり('after a gap of') is a useful suffix attached to time expressions meaning 'after an interval of X' — 一年ぶり ('after a year'), しばらくぶり ('after a while'), 十年ぶり ('after ten years'). It implies the interval was notable. しばらく ('a while') is slightly more than ちょっと but less precise than a specific time measure. 会う takes に for the person met.