Best way to setup Grafana under certain Conditions

I am currently using a local version of Grafana 9.1.0. I am relatively new to plugins, api, and all things related to setting up Grafana, yet nonetheless, I have been tasked with a project where Grafana is a requirement, so keeping it as simple as possible is optimal.

I will be recieving large packets of logs in JSON format every couple of weeks or so and want to be able to scrape the logs to be able to make metrics out of its key-value pairs. I.e. I want to be able to show a graph of zone temperatures from the data gathered in the logs. I was going to use promtail and loki, but it seems that just using that only allows me to display the logs in Grafana but not use the detected fields to use as metrics. I also have no direct communication between the computer I want to monitor and the computer I’m running Grafana on. Only the packets of logs that I’m recieving. Any advice would be wonderful!!! Thanks in advance!