I am sure many folks here will have plenty of good suggestions, but one right off the top of my head near your hotel is Sam Wo for fried rice. Pretty well regarded and I think it is some of the best I've had. Come out of the hotel, turn right up California to Kearney which is the next street (if you ignore the small side street called Spring St. which is actually just before Kearney). Right there for 3 blocks to Clay. Turn left and it is just on your left. Maybe a 5 minute walk on very safe streets. If you carry on straight from there to the top of the block you reach Grant St. which is the main (for a pun, shall we say "mein") street of Chinatown. Too many choices there

Alternate route: Left out of the hotel, go along Montgomery St. for 3 blocks to Clay and go left there for 1 block and Sam Wo is just across the intersection at Kearney on your left. This route has you at the base of the Transamerica Tower on the corner of Montgomery and Clay. Photo opp!