Lease agreement on a newly purchased propoerty

[Enyi Ajoku]

Hello fellow Landlords lol, 

i finally took the leap and bought my first rental property. Its a 2 unit multi property. Prior to closing one of the units was just rented out while i have plans to make some updates to the other unit before renting.

As regards the occupied unit, since it was already rented out by the previous owners i feel i need to revisit the lease agreement since the agreement on ground is between the tenant and previous owner and i am not completely confident on the terms of the agreement. Also with all the information i have gathered from BP and the resources available on FilePlace there are also addendum i would like to add to the (my) lease agreement. 

I do not have a detailed information of the tenant and i want to ask the tenant to fill out a rental application which will ask all the relevant question i need to know about the tenant.

I leave in upstate New York and i dont want to break any laws. Are these legal 

Will the little information i have tabled are there any other tips you can provide for me to be an informed and efficient Landlord.

Thank You

Enyi Ajoku