I want to meet up and laugh like the good old days as soon as possible.
Once the Covid situation improves, let's get together somewhere in the world, meet up and laugh like the good old days as soon as possible.
「早くまたあの頃みたいにみんなで笑い合いたいね」は英訳すれば、「I want to meet up and laugh like the good old days as soon as possible.」になります。
「コロナが落ち着いたら世界のどこかで集まって」の部分も追加したいなら、最初に「Once the Covid situation improves, let's get together somewhere in the world」を書けます。
そうすると、最終的な英文は「Once the Covid situation improves, let's get together somewhere in the world, meet up and laugh like the good old days as soon as possible.」になります。
ご参考になれば幸いです。