Fish tank water help?!?

I bought a 29 gallon fish tank it's brand is Marine Land and I bought it from Petsmart. I talked to a sales associate there and he told me that I ( living in the Acreage with hard well water) could use my water and tropical freshwater fish would survive in it. However when I set up my tank and went back to the store to get my water tested and hopefully by fish another employee told me that my hard water gave off high PH levels and alkalinity. So he told me if I put in a PH decreaser chemical as the bottle said until it was gone that I'd be ready for fish. I did that and it was still too high. Then they told me to take out half and put in purified water and then I could get fish. Well I did that and brought in my water sample and have the same problem. I mean the levels are going down but I'm still hearing " Oh do this and you should be fine to get fish." Well I do it and it's not working & I've had the tank for 2 months now and I'm tired of waiting and being disappointed. Are pH levels REALLY important? & Am I rushing into things? Is Petsmart screwing me over? I'm really tired of this!!!!! D:Also is it safe to buy a de-cloud chemical and use it? Why does my filter sometimes make clicky noises if there is no water in it? Are those plastic stick on thermometers really accurate? Do fish likes lots of plants and statues? PLEASE ONLY ANSWER IF YOU EITHER OWN A TANK AND HAVE PAST EXPERIENCE OR YOU WORK AT A FISH STORE AND KNOW WHAT YOUR TALKING ABOUT BECUASE I'M TIRED OF HEARING HOT AIR FROM PEOPLE'S MOUTHS. Kay thanks :)