Gas is verrrry simple in almost all single family home applications. If you test all the joints with soapy water (with the gas turned on) you will find any leaks very quickly. I know it's scary, but water will do much, much more damage in a small amount of time than gas. Of course, if you're simply not comfortable doing it, hire a professional, but trust me, if lazy apprentices who don't think past their next vape hit can do it, so can you.