I read a really good post on TechCrunch today that said if you are doing B2C - there is no value in joining a tech startup and you should just start. http://techcrunch.com/2015/09/13/youve-only-got-one-shot-to-build-a-consumer-unicorn/
The author countered that if you are doing B2B - then there is some transfer-ability and not just soft skills but perhaps industry connections may be useful.
Or you can come work for me, you'll learn how to set up and maintain legal entities. Working for us will provide important legal and financial experience that will translate for you as an entrepreneur in any industry - as you'll always need to form a legal entity and perform basic corporate governance as a the entrepreneur/founder/majority shareholder.
Happy to have you learn on my dime. :-)