Who else would have bought this land from them?

I want to avoid mistakes as a new landlord so hoping to learn from all of you! 

If not, I most definitely would reach out to the tenant, introduce myself and ask if they are going to be out by the 31st or the 1st, I would communicate  to the tenant as if I know they were told they are expected to leave, otherwise you may find they "do not know" they need to leave even if they actually know they need to leave....In the case they claim they are not aware they need to leave, you would need to follow the laws in the state you purchased the property, usually you can find that info on the states judicial branch or speak with a landlord tenant attorney. 

I've sold land in Bakersfield in 2023 and 2024. 

@Jacob W. land market in FL is highly competitive.

Another huge thing to consider is laws and regulations, many times new investors will jump at Hudson county thinking the proximity to NYC is great for renting (which it is) but many of the municipalities in Hudson county have very strict landlord laws. 

how much land and how much money do you have?

Quote from @Chan Park: It's time to step and be a Landlord, as uncomfortable as it may seem.

Showing them that you are aware that this is their space and that you are an intruder (landlord or not), can set them at ease by showing such signs of respect.

The current status of the market is low end rentals land lords that let the houses look like crap.