You might find this blog post (Graphing queue get/put rates) that I wrote for another purpose (comparing graphing in our tools) useful, as it starts by comparing the two main mechanisms for obtaining what you want, messages in and messages out.
You can ignore mention of the tools and scroll down to the heading "Which should I use?" for the details to help you.
Any questions beyond what is in that post, please ask them here.
These articles could be a starting point
AMQSMON https://www.ibm.com/docs/en/ibm-mq/9.2?topic=information-amqsmon-display-formatted-monitoringDISPLAY QSTATUS https://www.ibm.com/docs/en/ibm-mq/9.2?topic=reference-display-qstatus-display-queue-statusDISPLAY QUEUE https://www.ibm.com/docs/en/ibm-mq/9.2?topic=reference-display-queue-display-queue-attributeshttps://www.mqtechconference.com/sessions_v2017/MQTC_2017_MQ_Performance_Benchmarking.pdf