I'm from Newcastle (lived abroad all over and now back) and if you're near Central Station you're in Newcastle 'proper' and can walk everywhere you want to go within the city centre itself.
Chilli Padi is an AMAZING restaurant - Malaysian and Pan-Asian - it's just perfect. Happiness and Infusion 2018 are brilliant, too. You could join the group on Facebook called Newcastle Foodies if you're on FB, people will give you brilliant recommendations for everything including non-foodie stuff.
If you want pub-pubs then The Forth, Town Wall, Tilleys (all three a stone's throw from Central Station), The Old George between Central and Monument (walking about five mins from Central), The Crown Posada is an fantastic old traditional pub walking down from Central to the Quayside. Keep walking along the Quayside towards and beyond the Millennium Bridge to the Ouseburn where there are great pubs like The Tyne Bar, Ship Inn, Cumberland Arms and The Free Trade which has a lovely view up-river of the bridges from their beer garden. If you like fancy bars or cocktails you'll also be spoilt for choice. Loads of fab restaurants and bars.
In the very centre near Grey's Monument there's the old indoor market The Grainger Market with little foodie stalls like lush Chinese dumplings, gyros, a Spanish tapas type place, Indian street food, bagels, Cuban food etc. Well worth a wander and some fairly cheap bites to eat on the go. Definitely recommend it!
I hope you love Newcastle, I really do. It's such a great, walkable and easy to visit city compared to others where everything is quite spaced apart. If you struggle I'm sure you'll find friendly Geordies more than happy to help you, for the most part anyway :)