That will guide you as to timelines, ie if you are not going to renew the lease.However, you do have to honor whatever time is left on an existing lease. 

Many of them charge 40% of first month to get a tenant and 25% for lease renewals, as well as 9% per month for month-to-month management.  

If there were only a few months left on the lease, I would give proper notice of non-renewal. 

I have a tenant that is still living in my rental property, but I just received a notification in the mail that my tenant has yet to renew the renters insurance for another year. 

I’m anticipating I will start making commissions in 2020 forming a team with my mom on the residential side of real estate and I may be doing commercial lease renewals as well.

Look at the current lease to see when their lease is up, renew the lease and give them appropriate notice.

The notice must be in writing and direct the tenant's attention to the automatic renewal provision of the lease.

@Jerome Morelos If you need one of the units to be vacant for you, these are a few options:- Put a condition in your offer that one of the units must be delivered vacant before closing- Ask for the lease (as mentioned above) and see when it is terminated and check the renewal clause- Offer cash for the tenant to move out

Instead he found me a renter and consequently tried to have me sign a different contract to rent the house to him for 2 years with one year option not to renew, while he rents house to tenants, although my name was also on the contract with the tenant.

I believe it's roughly $800/year to renew?