Actually, you may need what is known as a limited cal.....that is, only certain functions/ranges are cal'd.....
To check continuity you typically seek less than an ohm or two and for voltage then check for some value. The short is not difficult, have a specific wire, say 6", 16 gauge and the meter should beep or otherwise show short, which for continuity is good. Voltage - if to see whether you are going to get bitten or fried, then have that cal'd. After all, even with a good meter, if it is not cal'd, I would not stick my hand into a circuit where that meter was used to read.....the meter could be wrong and if no cal, then there is no sufficient periodic check.
Just my thoughts.
Hershal