Two nearest ones are:
The Starting Gate outside Ally Pally train station (but not an “outside train station” pub - at least not any more) which is by far the best one if you’re coming from Wood Green end
The Victoria Stakes at the bottom of the hill (bit posh/gastropobby but en route if you’re coming from Finsbury Park
But if the weather’s good, just get some tins in, get up to the Palace and enjoy the view