This is one of the most important points in the comments here.
In LA opening a restaurant with only 50k is irresponsible mathematically. I say this having taken restaurant management courses with the goal of one day opening one myself.
It is true that restaurants are one of the most difficult businesses to start. It takes time to find your groove, and 50k no matter what neighborhood your in is not a lot of time. Most people in this situation would start with a food truck or save more.
$50k means you're a neighborhood restaurant, most dive bars and sandwich shops cost more to open...