On a more general level: First and foremost it is always ok to ask before frying (expensive) components or pieces of equipment. The next step of the learning process is to read and understand the datasheet of component - the sensor in this case. The voltage levels to safely operate the device will always be part of the datasheet as this information really is essential.
Typically there will be a "Specifications and Limitations" section, or a list of features that includes the operation voltages. Datasheets also often include an "Absolute Maximum Ratings" section which as the name suggests documents operational conditions (such as voltage, current, temperature) that must not be exceeded. Stresses beyond those limits may cause permanent damage or affect device reliability. Operations outside the documented ranges will also void the warranty.
In the case of the mentioned sensor the datasheet (as provided per NULL's answer) lists minimum, typical, maximum operation voltage (4.5 V, 5 V, 5.5 V). So the sensor has to be operated within a range of 4.5 V to 5.5 V. Undervolting at 3.3 V might actually not destroy the sensor but may (and will per joan's answer) significantly reduce the performance. It may fail at the most unforeseen moment or simply read nonsensical values. Simple put, it is not possible to use 3.3 V to operate this sensor.
The other answers already made it clear that the number of sensors to be connected is not limited by the number of 5 V pins. They also provided solutions how to overcome this limitation. Note that this only applies to the power rail pins and not to GPIO pins that support only a very limited current.
There is however one limit to consider - the current those sensors draw with respect to the power supply used. The sensor in question has a listed maximum working current of 20 mA. Which is not that much - but if ten sensors are used it will sum up to 200 mA which is starting to become significant. So be sure that the power supply can support the Pi, peripherals (like keyboard, wifi dongle, ...) and various sensors attach. To check this estimate and sum all the current demands and compare to the current rating of the supply. Check the RaspberryPi's power consumption for comparison.