how to connect humidity and moisture sensors in one arduino uno
Depends largely entirely what sensors they are. Make, model, link to datasheet?
In general: connect GND, Vcc (5V or 3.3V as needed by the sensor), and data lines to digital or analog pins as needed.
Power to the boards like marle said and then use the digital or analogread functions to get the values. Use if statements to do whatever it is you want with those values.