You have a very simple itinerary, you go to my favourite pub in London, Ye Olde Mitre and have a few beers there. You could eat there but then you would be limited to having old fashioned toasted sandwiches, cheese with either onion, pickle, ham or tomato (done in a toaster) and a pork pie. I haven’t been for a 3 or 4 years but that has been its menu since the mid 80s. They are very cheap though (£2 last time I went, £1 in the 80s). If you are looking for a bit more foodwise, walk up Hatton Garden and turn right onto Greville St on the right you will find the Bleeding Heart Tavern, the gastro pub of the Bleeding Heart complex. Eat there and be comforted that you are using places that have existed for hundreds of years.
I have a recollection you may not be of the male sex, The Griffin is a strip joint. If that appeals, stock up on £1 coins.