An attorney can draft an operating agreement that spells how the partnership will work but it's up to you and your partner to agree on the basic terms in order to tell your attorney what to draft. A good CPA can also help determine the proper structure for taxes and may even have some insight on how to structure your entity. It should be a team effort between the principals, your attorney and CPA. I would get them in the same room or a conference call to brainstorm what will work for you. Start with ownership % based on contribution amounts, then who is going to do what for the project and if someone is doing more of the work should they be compensated for that in either a fee, equity, etc. There is no right or wrong way to structure a deal, but there are better and worse ways!
Creating an entity is the easy part (in Indiana I can create and register an LLC and register an EIN online in about 10 min combined). I had my attorney draft a blank operating agreement that can be used for each single purpose entity I create to invest in a property. Each of those entities are owned by a single member, which is my companies parent entity (LLC) which has a different, more detailed operating agreement that lays out how the company operates, voting, control, management, contributions, distributions, sale/liquidation, taxes, etc. That's what works for my situation, yours may be vastly different.
*This is not legal or financial advice, consult an attourne and/or CPA.*