wind waker if you want a more nostalic feeling but it really dosent matter since both games have different timelines

wind waker hd was my first zelda game and i loved it! botw is awesome too

Depends on what genre you prefer, I suppose. Personally BOTW is more cinematic (I guess?) but Wind Waker is more stylistic and flowing. It's all up to you.

both are cool but ww is faster to beat. i highly recommend to start on it