You can use the Blumberg A-55 'New York Apartment Lease' these are standard forms that you can buy online or any stationary store (probably cheaper since they sell them loose)...I own two NY co-op rental and use it in both...another alternative if you work with an agent is using REBNY form which is very similar and would agent probably suggest with no charge to you.In addition I follow my old landlady (an RE Agent) practice of supplementing it with a rider (copied hers) in which I stress/modify/add term which are important for me (for example that tenant cannot Airbnb the apt).The co-op is a company which have their own interest which not necessarily align with yours...it just happen that sometime they allow you as a shareholder to sublet your unit.   

My plan was to do a combination of cold calling with social media marketing and then paying for advertising (like Facebook, Zillow, Home Light).

@Shawn Lawson meet-ups, social media places like Facebook groups, seminars like this one https://bec20.com/

On social media?

We have several ways of advertising our properties, social media, proprietary data base, and yes, MLS.

I don't know if you have a Big Box store card if there are advantages there. 

Check your local laws to see how long you have to store it-and yes as long as it is in a secure location, it is fine.

I want to be able to have a social media presence and connect them both.

The lease on the Dollar General will expire in ~6 months, and it looks like they will be leaving to build a new store.

The "entrepreneur" community on youtube and social media seem to be the preachiest with this topic.The people who wake up earlier just go to bed earlier.