You should sit down and research about rent, fixtures, food cost
as well as prices. From there, you can calculate your profit
margin. You must also calculate your daily breakeven point and then
decide if you can have to volume to sustain. Also think of your
cash reserves and consider how long can you go without making a
profit. It is likely when you 1st start off, the 1st 3-8mths aren't
likely to be profitable. You should also establish a point where by
you prepare to call it quits if it doesn't work out.
Again, if you are clueless at this point and coming here to look
for advice, I think you should re-evaluate your plans.
For F&B, you must think of a niche to attract people. Very
important is your location and your initial promotion efforts. Very
competition these days. It seems many try to do something of this
sort but fail. How are you going to compete? By unique menu? Lower
cost? Or by sheer variety? Consider these. How much do you want to
spend on your promotion efforts and the initial discounts that will
likely make you sell your goods at cost.
There is no set profit margin or standard costs. No point asking
here, best to go on the ground and conduct your own research. I'm
afraid asking here is letting yourself be mocked and seen as having
wishful thinking.