I feel like early Legend Entertainment games are a perfect gateway to interactive fiction since they do have some graphics and interface while still being primarily text-driven. My personal favourite is Frederik Pohl’s Gateway series (books are amazing too), but you could check out Spellcasting 101 and Eric the Unready which are available on GOG.
And if we’re talking classics I’d recommend Babel for starters, it uses very modern game design without softlocks and unfair fail states, almost entirely narrative driven with simple and satisfying puzzles sprinkled in.
Otherwise I’m a huge fan of anything by Andrew Plotkin.
Not a huge fan of Zork, it’s so rough to play these days without a guide. Maybe other Infocom games should be played first, like Planetfall, it’s relatively not so player hostile.