check your connection properly. if you dont have any experience with soldering get a pi i2c adapter or if check i2c voltage level for sensor. make sure they are same. if you use an i2c adapter it will take of i2c connections and all kinds of voltage level. you can check here. Raspberry pi I2C adapter
if you want to make it more easy then you can get a TSL2561 sensor with a i2c connector, using i2c connector you can directly connect sensor with pi in few seconds. and you dont have to worry about any wrong connection or voltage level.
lot of time devices doesn't respond just because of bad hardware connection.
after connecting all your hardware make sure you have installed I2C tool. if you have it then just run sudo i2cdetect -y 1 , it will respond with an address 0x39. at this point you are good to go.
you can find the code here. TSL2561 raspberry pi java,python code