Ocarina of Time is a pretty good starting point if you want to go with the 3D Zeldas (which are generally more fun in my opinion). The rest of the 3D ones (Majora's Mask, Windwaker, Twilight Princess and Skyward Sword) are all pretty fun, although Twilight Princess would be my personal favourite. BOTW is technically a 3D zelda as well, but its whole format is completely different. I also am not really far enough into it to give it a proper recommendation.
In terms of 2D Zeldas, my personal pick would by Minish Cap. It isn't too difficult or long, but it has a lot of charm and fun dungeons and items.