Welcome, @Wallace_Johnston. There is a LOT of great information in these forums.
The “How To: Get Calibrated!” wiki is excellent. I recommend going through all the wiki pages, actually. Also, dlang’s “List of sources of error”, and these benchmarking related threads: Triangular Linkage Evaulation Criteria and Measurements, BenchmarkAccuracyTest20180716.xlsx and benchmark database, might be of interest to you.