checking electrical drainage

I have a 01 VW cabrio and recently the battery has become stone dead a
few times. After I recharged it I disconnected the Neg. and put a test
light inline between the post and the neg cable and the light lights
up. Would the security led and clock timer use enough juice to light
up the testlight? I have an electrical test meter, can I use it to
test how many amps are draining, if so what is procedure and what is a
normal load while ther car is turned off? The battery is original and
might just need replacing but would like to know for sure. Thanks