Looks like you are surprised (and not in a good way) at what happened when you selected Flux in this dialog box? Can you go back and change it?
FWIW, as complicated as Flux looks, it’s not that bad if you use the InfluxDB Data Explorer to build the query using their GUI (using checkboxes and such). Then, when you have the results you want, toggle to the Flux editor mode and it’s just a matter of copying / pasting the Flux query into Grafana.