I'm not a lawyer and this is not legal advice.
I recommend finding a lawyer and an accountant that specialize in crowdfunding. Legislations on crowdfunding is constantly changing so keeping up with it on your own will be a nightmare.
These types of platforms are still relatively new so It might be hard to find reputable ones with good track records.
If you would like help finding reputable lawyers and accountants that specialize in crowdfunding, I can help you with your research.

Are you asking about software that translates the files for you? If so I wouldn't recommend using software translating anything. It's never really accurate.
My recommendation for translation would be to find someone on fiver or another freelance website do that kind of work. Make sure they are familiar with the VTT file format, they are proficient in the language or languages you want them to translate to. Also make sure they are proficient in the English language as well.
If you want further advice for where to find people like this, please, feel free to reach out.
Best of luck!

I, personally, would recommend Google Analytics. They are the best at gathering information on customers, web traffic, and user behavior.
They have a very good online course which I'll link here for you. https://analytics.google.com/analytics/academy/
I've been using google analytics for a while and I really enjoy it!
If you need any further instruction, other ways to gather user data, or would like someone in person to walk you through how to get it set up feel free to reach out to me.

Best of luck!!!
- Kyle