Breakfast- pickled duck,secret cafe,stables Inn or down the Quay to primrose or the coffee house
Lunch- sandwich co, guappo, any of the above places and most pubs do soup,sandwich and full dinner menu at lunch time - so Bentley, the thirsty goat, silver Street tap house there is plenty more youll see them all city centre
Dinner- Castle Street social,browns in town,exchange, el tapas gra,entrada, nonnas and again all bars are doing restaurant food - so if looking to stay on for a drink book a late meal and hope you get to keep the table!
I seen on Facebook brickwork lounge are doing basic bar snacks but have live music - really hard to recommend bars atm when they arent normal.
Blackbird also does food and has live music.
If down the quay Pyke n pommes do greaf burgers and tacos atm they are in bus you can sit on it or eat on the street.
Florentinis does the best chips - but only open during the day.
I asked about the car as you could go to buncrana - tank and skinny seaside is lovely for lunch and loads of nice walks that direction. Could stop at an grainan Fort enroute. Firebox grill is also thst direction with unreal steaks
Also ness Woods and roe Valley Park are nice if you want a drive and a walk- there's a nice waterfall at ness woods.
Taxis are cheap but can be hard to get so do try stay city centre if having a drink
Hope that helps! Sitting having breakfast trying to think so brain might not be 100
Enjoy it but remember times aren't normal ! And the craic isn't the same