There are certain foundational design principles that will never change. They are the source material for anything you create — no matter if you’re working on a website, a mobile app, an ATM machine, a virtual reality experience, a poster, a TV application, a digital kiosk.
Start here: visual hierarchy, information architecture, balance, alignment, composition, proximity, continuation, repetition, framing, mimicry, readability, contrast, consistency, affordances, feedback, orientation, similarity, closure, horror vacui, symmetry, inputs, navigation.
These should give you enough to focus on for the first 10 years of your career. Master these. Really master these. Strive for perfection. Improve your skills. Rinse, repeat. You can never un-learn such principles. Technology will always change; these won’t.Designers: the only certainty is change