First you need to read the Influxdb docs so that you understand the concepts in influxdb. Make sure you read the right docs for the version you are using (1.8 or 2.0) as they are very different. I think most still use 1.8, waiting for 2.0 to fully stabilise.
Are you going direct to influx from telegraf or are you writing to the database from node-red? If using node-red then, once you know about Influxdb Measurements, Fields and Tags, then you can use node-red-contrib-influxdb to write (and read) to the database.
Thanks for the information.
I want to implement the solution according to the best practises. to be honest, I don't know what the pros and cons are of either solution. I'd like to keep it as simple as possible.
If Telegraf does what you need then you can go straight to Influxdb from there. If node-red also has access to the data then you can go via node-red. There isn't a best practice, it depends on what you want to do. I suggest spending some time reading docs, then have a play and then decide which suits your requirements best.
I'll be reading some more information regarding these topics. As I already use Node-red for certain automations, I'll prefer to use it for this solution as well.