Why not just request the annual report from your local utility (or look online)? If your main concern is hardness, it should tell you that.

Testing your own water may or may not tell you anything meaningful. For basic parameters- TDS, alkalinity, hardness, copper, iron, and lead, it might be representative.

But what you're really doing is just catching a(n expensive) snapshot of something that may change daily and seasonally. Your utility makes water 24-7-365 and also is required to monitor its quality a lot more frequently than the one minute on the one day of the year that you'll pull a sample.

I know that approximately half of the country doesn't trust the government any further than they can spit right now. But I think you'll pay for your testing and not find out much that you couldn't have gotten for free.

And most folks filter water mainly to remove chlorine because of the taste. The lab won't test for that because it changes/decays over the time between sampling and analysis. To test for chlorine, you need to do the analysis right at the sampling point.

My wife's office tested their water and spent a couple grand doing so, certain they would find a smoking gun of something unhealthy they needed to invest in an expensive filtration system to remove. Results- nada. YMMV.