What is the output logic levels of this STM32?
What will be the output voltage levels?

The first thing to do is choose Vdd, which for most designs is 3.3V (you can choose Vdd to be anything that is within the processors operational ratings in the datasheet)
Then you need to figure out what the load current will be on the GPIO of the STM32 (should not be more than 8mA sourcing and 20mA sinking there are also limits on how much the sum of sinking and sourcing current is for the whole part, if I remember right it's something like 25mA or 50mA for most STM32's (check the datasheet for your part).
If the Vdd is 3.3V as long as the current is less than 8mA the voltage of the port will be more than 2.4V (Voh) and this is guaranteed by the datasheet.
There is a good description here of digital logic levels: http://www.interfacebus.com/voltage_threshold.html

Source: http://www.interfacebus.com/voltage_threshold.html
This is also good: https://www.allaboutcircuits.com/textbook/digital/chpt-3/logic-signal-voltage-levels/