That’s correct place your black probe to ground and touch each transistor pin with your red probe with your meter set to 20V DC
So you’re not getting signal into the Gate of Q1 is that correct the pin with the arrowhead on it in the schematic?
I’m assuming you’re using an unregulated power supply with over 10v that would affect the voltage going into the JFET 2N5457 Q1 and Q3 these are voltage controlled devices
If you don’t have audio going into Q1 then your problem lies prior to it C1, R2, R3
R2 and 3 form a voltage divider giving you half the power supply 4.5v
Here’s the transistor pinouts you can find this information in the datasheets or by searching 2NXXX pinout which I find easier to do there is some information on page 15 of the beginners guide to components
Q1 and 3 2N5457
Q2 and 4 2N5088