[klondike98]

Welcome to the Phorum!  
Take a deep breath....go slowly...you can do this.
I don't see a schematic for an 18 code 121 on Nostslgiaair.com and the code 124 schematic is tough to read.  This will make it a little more difficult to help but there are lots of generic things to pay attention to.  As the guys earlier said, you will need to replace all the electrolytic and paper caps.  Arran mentioned bakelite block caps.  You'll find help for those here and here.  Be certain you have the polarity of the electrolytic caps correct.  Check resistors to see if the need replacing.  Check transformer windings and all coils for continuity. Check tubes. 32 mv across the rectifier plates is way too low so something is amiss.

Go slow and methodically, ask questions as you go and post pics if needed.  Lots of folks to help you.  Here's a good first read for beginners.  If you haven't already done so, a good source for schematics and documentation is here :  http://www.philcorepairbench.com/schematics.htm