As suggested by many members, I also use speedtest-cli which is a python script, After downloading script to your server. Run script using python command like "py speedtest-cli" or "python speedtest-cli"
For disk test, You can use "dd" command which is so easy to run.
Yes, server location do matter. IF the location is far from your targeted audience . They website may load slow on their location. You can have a CDN service to have your static content delivered from a CDN service.