Complex sentence: Since the very beginning of the war Baković family newsstand was a central hub for connection of members of Zagreb resistance movement where they would leave letters and packages and arranging meetings, and place of supply for the League of Communists of Croatia where Jerko worked.
Split into simpler sentences: Since the very beginning of the war the Baković family newsstand was a central hub for the connection of members of the Zagreb resistance movement. They would leave letters, packages, arranging meetings, and was a place of supply for the League of Communists of Croatia where Jerko worked.