In Depth Analysis: から kara indicates starting location of action or function, origin indicates the first of some order indicates the point or gate to go through indicates the cause or reason indicates the material of which something is made に ni indicates location as a result of some action or function indicates thing which is a result of some change indicates person or thing of, from / to which the action or function is done indicates state or environment in which the action or function take place indicates the object to which measurement or comparison is done indicates the purpose of the action or function Basically, から indicates more specific meaning, which is almost the beginning or location of starting from. Almost 'From'. And に indicates an object or location or state related to a result of an action. It's translated as 'at', 'to', 'from', 'in', 'for',,,. I hope this didn't confuse you, it's quite hard to grasp at the beginning.

私は"職場"から来ました（I came from my work place.） is better. You can use "～から" as "from". But we don't say "しごと　から　きました". I think when I use "～から" with "きました", I only say about some place.