Illumination Sensor (BH1750)
it uses I2C-bus and gives lightening levels in lux.
The sensor can be obtained for ~2€ (if ordered from China)
The library can be downloaded from https://github.com/Genotronex/BH1750FVI_Master and coppied into the arduino library folder.
The Arduino Nano uses analogue port A4 and A5 for I2C.
Temperature & Humidity Sensor (DHT22)
the DHT sensor is using the Serial Periferal Inerface (SPI), which allows any digital port to be used.
The corresponding library can be obtained via : https://github.com/adafruit/DHT-sensor-library.