first house hack. need some advice

[Will Kirkendoll]

hey Bp so Im going in be closing on first house hack in a couple weeks. its a duplex with one side already rented out. tenant been there 3 years and on month to month lease but still wants to stay.. according to seller. my question is how do I inform the tenant that I will be buying house and where to send payment too?? i will do my own property managent under my property management llc . also should I make the tenants sign a new lease?? thanks bp