''work at software company'' is habitual action. for habitual action ,we use simple present tense . and in simple present tense we don't use 'am' with ' i '. If you want to describe information about something at that time you can use 'am' with ' i '.

"There" is used for place and "These" is used for anything like person animals any thing (object) when these are in number of quantity. Ex:- These people, These animals, These chocolates, these plants. we can use "These" with any object when it is number of quantity.