Multimeter, outlet and a Spark: the question of simple Voltage measurement
Page 16 of your manual:

2.2 DC and AC Voltage measurement

1) Connect the black test lead to "COM" socket and red test leads to the
"VΩHz" socket.

2) Set the selector switch to desired “ V [squiggle]” position, and press
“SELECT” key to choose function.(DC or AC)

3) Connect the probes across the source or load under test.