Hi, bailey4yrs. I'd like to know where Chester is located. What state, province, . . . ?
Transplanting soil is a great and conservative idea, but only if the structure is par. You just might have missed a prime opportunity to incorporate organic matter, sand, silt, or clay, whichever was needed if any. Soil testing is something I strongly recommend because it will not only give you clue of the soil composition and recommend components, but it will also tell you of the nutrient content of the soil, as well as the pH balance and recommend amendments, such as lime or sulfur. You want to know these in order of maintain the sod you are about to lay. And, yes, I would remove the grass and weeds first if you're laying sod (although you don't need to if you are sowing seeds). Don't lay that much soil over existing grass because it will create a root barrier, and you'll later end up wondering why your new grass is dying. It will be because the roots don't have room to grow like they should. You first want to break up the grass and root system. Then, you can just use the mower to mulch it all over the lawn area as you spread soil. It will then serve as good organic matter and eventually decompose. Otherwise, use a sod cutter to remove it all, then carry it away, then resurface and level the area.
Call ahead for test kit and sampling instructions.........
If Chester is in the US, you can locate your nearest state university [url=https://urbanext.illinois.edu/netlinks/ces.html]cooperative extension service here[/url]. Once arriving at your state cooperative extension page, go to the county (or parish) listing and find your nearest one. Here is help to [url=https://ohioline.osu.edu/hyg-fact/4000/4028.html]interpret test results[/url].
If Chester is in Canada, here is a [url=https://www.canadiangardening.com/how-to/gardening-resources/testing-your-soil/a/1780]list by province[/url] and help to [url=https://www.gov.pe.ca/af/agweb/index.php3?number=74158]interpret results[/url].
If Chester is in the UK, here is a [url=https://www.agregister.co.uk/product-404750.html]limited list of labs[/url].
If Chester is in Australia, [url=https://www.aussieweb.com.au/directory/category.aspx?cid=2568]this list[/url] will help you locate labs and services.