And in terms of frequency, outside rush hours its kind of a train every 5 mins (so in a 15 min period, 2 are Overground, one Southern to London Bridge). A bit more frequent in morning rush hour.

And welcome to Honor Oak Park. Lots of hills and green space - One Tree Hill, Blythe Hill, Horniman Gardens, Hilly Fields (or take an OGround to Crystal Palace). Not huge numbers of restaurants locally, but there is a highly rated, if rather pricey Indian (Babur) and an Italian, La Querce both within 5 mins walk of HOP station.