Does this look like Greek to you? You're not alone. Multimeter function dials are often labeled in electrical symbols and pictographs. 

Your multimeter comes with two insulated probes. You'll need to connect them to the right ports (terminals) on the device depending on what you'd like to measure.

Use your multimeter to test old batteries for signs of life. The black probe goes on the negative side (flat end) while the red probe touches the positive (raised bump) end.

With a confirmed 1.5 volts of direct current, my multimeter proclaims this AA battery alive!

Use your multimeter to verify if a suspect switch is working or has failed.

An operational light switch will have a low resistance when in the on (closed circuit) position.

When your "simple" home improvement project starts to look like this, the precise measurements of a multimeter might be your only salvation.