Answer to Question 1
When you using a meter for the first time, you should always check the leads for continuity, which means you should set the meter selector switch to a resistance setting, and then touch the leads together. The meter should show zero or low resistance. If it does not, you should suspect the leads are bad, or the meter has a blown fuse or a bad battery. You should make the repairs as needed until the meter shows low resistance reading. When using the meter to make a voltage reading it is important to verify the meter is operating correctly, by measuring a known voltage source and ensuring that the meter indicates the proper voltage. If the meter does not indicate the proper voltage reading when you place the tips of its leads on the power source, you should suspect the meter is not working correctly and you should not use it until it can be verified as working correctly. The problem could be bad meter leads, a blown fuse in the meter or a bad meter.
Answer to Question 2
The ohmmeter uses in internal battery to create the current that makes the meter movement move. Since a battery slowly goes dead over time, and because each range in the meter uses different circuits of internal resistance, you must always zero an analog