The lack of answers makes me think that I must be misreading your question.

With your start time in B2 amd the end in C2 then surely
=C2-B2 formated as time will give you the answer you want.

If you want to sum all the individual times and they are likely to amount to
more then 24 hours then format the total cell as [h]:mm to prevent the hours
rolling over into days at 24 hours.

To calcualte you income then multiply the hours by 24 and then by the wage
rate.