Inherited tenants lease adjustments

[Justin Butterfield]

I just purchased my first four Plex and the current lease from the previous landlord doesn't have a late fee at all or a date for when if they don't pay the eviction process will start. I understand I must follow through with the current lease until it expires and then I can have them sign my lease. My question is being I'm stuck with the previous landlord lease will I be able to make any changes to the lease or add a late fee.