Focus on Russia. They’re your main problem. Tip with that- get Russia to not see you as a threat and see Japan as a major enemy. Get them to move some troops to fight Japan. that will give you a better chance of quickly taking Russia. (Send everything to Leningrad, then smash through to Moskva)
Use your fighters and fleet to keep the Channel clear for a later invasion of Britain. Once you have Moskva, it shouldn’t be too hard to take Britain.

Or, just build infantry in Moscow and pull everything back except the first line.
This is a strategy that will make Moscow nearly impenetrable. As Germany treks across the Russian territory that has only one infantry each spot except the front line, Britain will be pouring their entire strength into invading from the opposite side.

With your starting 12 IPCs, build one artillery and a transport for the Baltic. Then, you should easily be able to take it with the support of a couple fighters. Make sure you attack Vyborg as well, so that if you lose Leningrad, you can push those in.
Also, a bold move that will prevent the Allies from stopping you too soon is to use all of your subs to take convoys. Then the British and navies will want to take those back before attempting to fight you. Btw, that makes America lose 10 IPCs and Britain lose 15 IPCs, as well as Russia losing 4. So really limits them at first. Won’t last, but is a major handicap.

Focus on Russia. They’re your main problem. Tip with that- get Russia to not see you as a threat and see Japan as a major enemy. Get them to move some troops to fight Japan. that will give you a better chance of quickly taking Russia. (Send everything to Leningrad, then smash through to Moskva)
Use your fighters and fleet to keep the Channel clear for a later invasion of Britain. Once you have Moskva, it shouldn’t be too hard to take Britain.