Taste (design taste, specifically) is a mysterious term.
How to acquire taste? Expose your eyes to millions (yes millions) of works of art. Websites, campaign ads, brand identities, films, documentaries, movie posters, etc etc. Make it a habit. Become someone who's seen hundreds of millions of designs. The top 2% of those designs will vastly differ from someone else's top 2%, if they've only seen a hundred thousand works in their lifetime. VASTLY.
How to design with taste? Take that mental exposure into your work. Replicate it through years of pushing pixels, learn the visual nuance that brings a design from good to great. Learn how the sub-components of great design are built from the harmony of delightful composition. Things like lighting (how much? how little? how focused?), texture (subtle? overt? scale?), typography (just wrestle til you get this down), etc.
Taste will advance your output working alongside AI. It will inform your prompt writing. It will build your confidence in pitches. It will differentiate your work all around. But you have to put in the exposure time AND the hard work to develop the technical execution. Even more work required to explain it with words. But the net pursuit is still worth investing in developing it.
Never stop the pursuit.