Generally, if KLM has arranged accommodation and meals for you, they will notify you by email or phone. You will need to contact KLM's customer service center or visit the KLM counter at the airport so that they can provide you with more detailed information and assistance.
Please note that if your flight delay is due to weather or other force majeure reasons, KLM may not be able to provide you with accommodation and food services. In addition, if KLM does not make accommodation and catering arrangements for you, you may need to make your own arrangements or seek assistance from another airline.
In summary, if your flight is delayed while connecting in Amsterdam and KLM arranges a subsequent flight for you, it is recommended that you contact KLM's customer service center or go to the KLM counter in the airport so that they can provide you with more detailed information and assistance.