To drive out the Jews, because he hated the Jewish people, and he was a Anti-Semitic.
Poland
He didn't want it, but he was prepared to do things (like invade Poland) that might result in that.
so he could fight a one a sided war with Poland, without having to be bothered whether or not Stalin would invade
Warsaw
The army decided to invade the enemy's territory under the cover of darkness.
because russia would get some of Poland to keep, and russia didnt want a war with Germany, so they signed the German soviet pact
Poland
No.Hitler invade Africa because He want some camel for ride and some Lion for pet
WW2 started when Hitler wanted more land and started invading surrounding countries. After a year or so Japan made an allience with Germany and attacked Pearl Harbor which is when the USA joined the war.
Hitler wanted to keep allies with Russia of which Poland was a neighboring state.
Because Britain & France had agrred with Poland to protect Poland from Hitler's attack. The similar aggreement was made to Czecholsolvakia and they self interst minded had led them failed to fulfil their agreement and ask the Czech to surrender to Hitler. They won't want to lose face again and had enough of Hitler's nonsense.
Hitler knew a war was about to start- he wanted to invade Poland, which was allied with France and England. He did not want to repeat World War I, where Germany was stuck fighting against France, England and Russia at the same time. So he made the non-aggression pact to keep the Soviet Union (Russia) out of the war. This was successful. Eventually Hitler broke the treaty and attacked the Soviet Union.