27 Inch 5K Studio Display Calibration

HELP!!

I have a small photography business and I can't-- for the life of me --not without hours of trying-- figure out what is the best way to calibrate my studio display monitor. I've read many posts that say you don't even need to ever calibrate it? It's not that I'm noticing gross color abnormalities, but I have gotten some print samples back from a few different labs and some of them were different so I thought perhaps I should try and calibrate the monitor. I'm not using it eight hours a day, but I have had it for a couple years. I bought a fairly expensive display calibrator-- the calibrite display pro HL-- and even with that I'm moderately overwhelmed! I tried the fine tune calibration option in the Apple pro display calibrator. I entered the numbers but nothing seemed to happen. I noticed that the 'reset all' button is grayed out so does that mean that my display doesn't even require a calibration? I'm sorry to have so many words and sounding so flustered but I bought this display Calibration tool but maybe it was overkill? I truly thought that the display would need some re-calibration at some point?