When you first create your Threads account through Instagram, you will be prompted to follow everyone you already follow on Instagram.
Threads: How to follow everyone from Instagram
You might have second thoughts about clicking the follow all button because you're undecided, so you skip this part so you can start seeing other people's threads.
Later you decide and you decide you want to follow everyone you already follow on instagram.
However, you don't know how to follow everyone again after skipping this part.
