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Firstly understand how to measure the voltage and current. Please use Google if you don't know.
Then it will be obvious that your don't 'stick it' on the MAX7129 chip but you can simply use the power pins on the module to measure voltage and current in the normal manner.
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No, the power pins consists of Vcc and ground. The rest are signal pins.
Din, Cs and Clock are not power pins.
"The problem i face now is i have no idea how to measure the voltage and current of the led matrix. "
When running, the matrix will be multiplexed at 800 Hz, you will be able to get meaning results with a meter.
[edit - meant to say Not be able to get meaningful results - only that an LED is being driven]
The OP will be able to get an average current reading. That could be useful for estimating battery life for example. An average voltage reading would be a bit meaningless.