I want to translate a video (manually) and subtitle it. I understand how caption files work and can do it by hand, but as I've never done it, it seems daunting with a lot of room for error.

I'm wondering if there is a tool to help with this, or just ask, if anyone has any experience with creating captions and what the best practices are.

Note: I do not want to embed the subtitles into the video, I just want a separate file, either .vtt or .srt