Newbie: Looking for Partnership Structure Advice

[P.J. Mellana]

Hello everyone, P.J. here and I am an absolute rookie here and looking for some advice. Just a bit about me, I'm in Southern California and am looking at vacation rental properties out of state and have already found a really good realtor/property manager that I am extremely confident in and trust. 

Now to my question, I have a potential partner that may want to come in as a 2nd investor with me. Between down payment and closing costs, I would be putting in 70% and they would put in 30%.  We're looking at traditional 20% down and mortgage for 80%. What are the simplest ways to structure the partnership? I'd like to just save the cash flow and not touch most of it for the first several years to build up an emergency fund. Any and all advice would be greatly appreciated.

P.J.