GoldWave Inc.

Hello,

I have .wav file and it should have 16 bit, 8000Hz, 128 kps, mono.

But it is 16 bit, 44100 Hz, 705 kbps, mono.

How can I change hz and kbps.

There is no option for that.

Effect -> Resample -> 8000Hz.

NOTE - For uncompressed files you don't have to manually set the bitrate (kbps):
16-bits x 8000 samples per second x 1 channel = 128 kilobits per second.
16-bits x 44,100 samples per second x 1 channel = 705.6 kbps

But suppose you want 44,100 samples per second and 128kbps. How can you choose those attributes?

You'd have to use a lossy format such as MP3.

With uncompressed formats everything is proportional... If you double the sample rate (kHz) you double the bytes-per-second and the bits-per-second (kbps), etc. (There are 8 bits in a byte.)