A short walk from the Convention Center, you have Euclid Hall with, MORE beer, sausage pairings, chicken and waffles and the like. Osterio Marco, on Larimer, for roast chicken, wood fired pizzas, burrata with leeks. I do think they do takeout. The 16th street free people mover really opens up your access to the entire downtown area. You can take it right down to the newly refurbished Union Station. Beautifully re-done and worth a visit. There, you will find Zoe Ma Ma, an offshoot of the one in Boulder, hand pulled noodles, excellent dumplings. Try the Lion Head or Braised Beef. Very good for takeout. You will also find The Kitchen Next Door, also a good take away option. They do great salads, pulled pork sandwich, great meatball with soft polenta and the ubiquitous in Boulder and everywhere else, kale salad. Still at Union Station, the Mercantile has great upscale dining but they also have a market with great house cured meats and cheeses for another good to go sandwich option.
Check out ChonLon for amazing "non-authentic" onion soup dumplings and other great dishes.
If you can get away from downtown and into the Five Points neighborhood, try Cart Driver in a re-purposed shipping container, for amazing woodfired pizza, oysters, and prosecco on tap (if you get sick of beer) or their next door neighbor, Work and Class -- meats by the pound, the cabrito and cohinita pibil are worth the inevitable wait, and the house batched cocktails are quite delicious. For more shipping containers, Avanti just opened in the LoHi neighborhood, about a 15 m
That should get you started. In the link that Sneak gave you, above, The Source is great but not conveniently located to downtown. Crooked Stave is amazing if you have a passion for sours and Acorn is great for both their shared plates -- try the charred octopus -- and craft cocktails.