how many countries fell under Nazi germany during the war? Which were the first?

Answer 1

The first was Poland,then Belgium,Luxembourg,and France.

Answer 2

Poland was first by conquest, although some people might count Austria and Czechoslovakia as first, but those are three. Then there's Belgium, France, Luxembourg, Holland (some might count Gen. Franco's Spain also) and half of the USSR, Hungary, Greece, Albania, Romania, Bulgaria, plus ... you might count Italy, then the countries across Northern African, including Morocco, Algeria, Tunisia; then there is also Norway, Denmark and Finland; the Balkan states of Latvia, Lithuania and Estonia (can you count those as separate countries?

Basically all of Western Europe except Switzerland, Britain and Sweden and Portugal

Answer 3

Well not exactly, Britain and USSR were the only "European" countries that did not "fell" under nazi occupation.
Then there were those who willingly and without any resistance sucumbed to Nazi Germany like Denmark and Switcherland , All of western Europe (except UK), Italy started as an ally to the axis but ended as an occupied country as well.