I'm finally planning to travel overseas for the first time in three years.
I'm planning a trip abroad for the first time in three years.
It's been three years since I've travelled abroad, but I'm finally planning to go to Paris this October.
「3年ぶり」は for the first time in three years のように言います。
ーI'm finally planning to travel overseas for the first time in three years.
ーI'm planning a trip abroad for the first time in three years.
「3年ぶりに海外旅行に行く予定だ」
または次のようにも言えます。
ーIt's been three years since I've travelled abroad, but I'm finally planning to go to Paris this October.
「（最後に）海外旅行してから3年経ったが、やっと10月にパリに行く計画をしている」
ご参考まで！
カナダ 
