How to prevent the second World War as Hitler

To an extent, it comes down to RNG (because of USSR, Italy and Japan), but here's how you can delay/prevent it:

• Do not remilitarize Rhineland at the start.
• Focus on your own infrastructure, by Reichautobahn line
• If you want, get Army Inovations II, but don't get the Molotov-Ribbentrop pact
• Wait until Italy tries to join the Axis, same for Japan.
• Don't freak out if Japan and Italy are fighting China and Greece, respectively
• Invest on Naval Rearmament, and go for Plan Z.
• Befriend everyone, but leave Netherlands for last (Japan won't like it)
• You should have a lot of accumulated Political Power, so spend it on boosting fascism on your new friends (They will eventually ask to join Axis)
• If the Soviets invade Poland, quickly focus on the Molotov-Ribbentrop pact, as it's likely they'll gift you half of it (Without you going into war)
• If everything is clam, now you can focus on Rhineland
• Go for peace, unite with Austria (Anschluss)
• Then Demand/Befriend Czecholovakia/Slovenia (hopefully the UK will allow you to after the London Conference)

This can take you very far, as far as 1944/1945, while building up your army and your provinces without going into war. The issue now is that the Commintern will try to expand, and if they are afraid of attacking the Axis, they may try to go for Turkey/Iraq/Iran. At the same time Japan may go for Pearl Harbor, which will drag you into a war with the Allies.

Which is fun, because in theory the Allies will only be France, US and the UK, and the Axis should be Germany, Japan, Sweden, Norway, Denmark, Slovenia, Croatia, Czhecoslovakia, Netherlands and Italy.

So instead of a World War, you'll have two big wars, with Allies vs Axis, and Commintern vs neutrals. This isn't too bad, because You won't have to worry about the Eastern Front, and if you blitzkrieg France, set up defenses on the coast and send your ships to blow up the British Coast, it will be fairly easy to win that war, thus preventing soviet intervention.