Complex sentence: During graduation he worked as Part time Accountant in various firms and shops, but he never want to make his career in accountancy, so he done Diploma in Graphic and Web Design and start working as Graphic Designer.
Split into simpler sentences: During graduation he worked as Part time Accountant in various firms and shops, but he never want to make his career in accountancy. So he done Diploma in Graphic and Web Design and start working as Graphic Designer.