You should have a good understanding of Geometric Dimensioning and Tolerancing (GD&T) fundamentals. The ME department at SJSU offers a Manufacturing Processes class (ME101) which covers some GD&T fundamentals. If you’re more ambitious, you can take a graduate class, Precision Machine (ME 250) which touches on GD&T as well.
This is a good website for looking up GD&T symbols: https://www.gdandtbasics.com/
You should also have an understanding of RSS Stack analysis. Any company/manufacturer that produces large volume of products (Tesla, Apple, etc.) uses statistical tools to monitor the accuracy and precision of their parts. The key thing to understand is that RSS is a 3 sigma based analysis and only applicable for large number of manufactured parts. Here is a website that explains it pretty well: https://www.brighthubengineering.com/machine-design/56403-assembly-tolerance-stack-up-analysis-using-the-rss-method/
You should also know about Metrology terms: accuracy (how large or small is your error), precision (same as repeatability), resolution (smallest discernible change), etc.
Look up Coordinate Measurement Machine on Youtube and understand what it does.