Help writing a lease for a rookie!

[Nicholas Pisano]

Wife and I closing on our first house-hack in Ulster County. We are inheriting tenants in the upstairs apartment and need to present them with a fresh lease. 
I have no idea what I’m doing re: drafting said lease :)

I am using a site calls EZlandlordforms.com to give me templates. The free version is a super basic 3-page lease. The paid version is 69 pages long and by far the most intense lease I have ever seen. I definitely plan on paying for the pro version (it’s like $75 a year or something). Would love some insight on how to add or remove clauses from this thing to make it more digestible and relevant.
Are there any “must-have’s” in your lease templates? What do to wish you knew in the beginning?

Any advice greatly appreciated!