I invested in a small small start up business in the USA

I was invited to be an investor for a friend's start up business in Michigan USA. I have given capital for this since 2014. I agreed for it to be on sole proprietorship under my friend's name for the moment. Since 2014, I've been giving him advice and volunteered my resources in order to make it grow. Recently, the owner has invited me to be a full partner and he wants it to be an LLC corporation, since I am a Filipina I don't know what I need to do in order to formalize this. It's a small business and I want to know what steps to take and what requirements I need to produce (like documentation from the philippines) to make this happen. Would appreciate also any referrals to someone who can help me out.

I don't know the American laws,
but I suppouse Partnership type of business is as in some other countries
=In relation to OTHERS the partner is FULLY responcible if the OTHER partner mess up...
=If the business can't pay, then others can demand WHOLE pay from ANY of the partners, so you risk to pay ALL if the other mess up and can't/don't pay.

My uncle (married to my blood related aunt) had a partner in a TV and music shop. The partner STOLE all products, but my uncle had to pay all depts and rents anyway...

So I recomend people to NOT make Partnership businesses. I don't know if they have a similar type of business in USA.
= One or more are part OWNERS, and can decide to NOT do changes,
but they CAN'T decide CHANGES without the "complementary" owner agree. The "complementary" person has to sign deals to make them valid. The owners only risk the capital they have put in, while the "complementary" person has to pay the rest if money is missing. That's why the "complementary" person has Veto against things, not decided before he agreed to be "complementary" person.

If they have such in USA, I recomend you to get such.