One of my favourite pieces of world building advice came from the late great Terry Pratchett, who figured out how the plumbing would work in his Discworld and built up literally from the bottom upwards! Well it IS a place to start... and a vital one. (After all in the UK where would we be without Sir Joseph Bazelgette and the sewer system he gave us? Up the proverbial creek.... literally too!).
I've started with looking at how the form of government would work in my fictional magical world and that led to me working out how villages would be, what kind of media there would be and that my creation was not above pinching ideas from other worlds it kept an eye on. What I found was that one idea for filling in the details about a practical side of life my characters would have to live with is that this inevitably led to more ideas and my fictional world came to life piece by piece. The more realistic it seems to you, the more convincingly you will write about it and the characters that live in it and that really will be picked up by readers.
So some questions to ask then:-
Where will you start with your world building?
Who does sort out the plumbing and how?
Who runs the government and what kind is it?
How is magic used? Is everybody magical or do differing species have differing abilities? Is there scope for someone with relatively low levels of magic to improve themselves and their capabilities here?
How is education carried out?
How is society organised?
Enough there to be getting on with I think!