Network Utilization and Optimization

Hi all, am new to networking.
I would like to ask for the scenario below:

1.If my own developed software transfer a file to server, how can I know the network utilization of it?

2.If the same file (let say 5mb PDF), I want to transfer on the slower network, let say 128kbps, I would like to know how it will congest the network and how long it will takes to the server? Of course there are other utilization like email etc.

Thanks.