@Michael D. Congrats on the new property. It sounds like the numbers are pretty good!
Inheriting tenants will become pretty standard as you continue to purchase buy and hold. We typically wait a couple months, say 2 or 3 before we make any significant changes when we purchase a new property. Just like you mentioned most tenants are worried when a new landlord buys a building because they think there rent is going to go up or they are going to be told they need to move out.
The first couple months are about the tenants. We setup a walk through of the unit and do a meet and greet. We have our staff ask if there was any pending maintenance items the past landlord or property manager didn't fix for them. This is key because it shows you are not going to be a slum lord and you will fix things in the unit if they break (although we will charge them if its something they broke)
We are also testing them to see if they pay rent on time and how they keep the units. Depending on current leases etc we then plan rent increases as needed and get everyone over to our leases within the first 3-6 months. There is nothing saying you can't increase rent asap but I've seen owners do that and it causes a lot of discontent and I'm more focused on stabilizing the property first and then rent increases come next.
The most important thing is getting them over to leases. You want to have all of your units on standardized leases. Makes your life easier.