The tenant can trying negotiating with the landlord if they cannot afford to pay rent. Sometimes a landlord may be more interested in keeping a good tenant than receiving extra money. For example, the landlord may not raise rent if the tenant offers to help with tasks like painting or shoveling snow.
If the landlord will not negotiate, the tenant can find a way to pay rent. Or, they can find a less expensive place. If the tenant decides to move out, they must give proper notice to their landlord to end a periodic tenancy.
If the tenant does not pay rent, the landlord can serve the tenant with a 14-day notice to terminate for non-payment of rent and the tenant can face eviction.