Under contract on my first multi family in New Hampshire

[Annie Gillespie]

Hi everyone, I'm new to this forum and haven't posted but have done a lot of reading! This site is so helpful and has given me so much knowledge. 

I am under contract on my first property, its a three family in Manchester, NH. 2 units are rented, 1 is vacant. We met the tenants in the 2 occupied units and both seem nice and units are well maintained, they are both current on rent.

I am excited and nervous! My husband and I plan to manage the property ourselves, we live about 2 hours away currently, we are buying in New Hampshire due to the fact we plan to move there within the next year. 

I nervous about the process of renting out the vacant unit, and creating a lease to use. Would my best bet to be meet with a lawyer to create a general lease to use on all rentals in the future? How should I go about tenant screening? Are their websites people can recommend for doing background and credit checks? The property is in a B area so I should be able to get decent tenants, and want to make sure I screen properly. 

How many hours are usually invested in filling a vacancy?