I’ve found newer players try to keep the US out of the war until the US can declare.
When that is the case, just build enough of a fleet (probably US1 is 1 battleship, 2 carriers) and move every aircraft to Hawaii.
After that Japan has probably lost itself the game in the Pacific and you just need to plan on convoying her out of the game and destroying her ships so she cannot expand.
The rest of your IPC should go towards your first landing fleet in Europe. Remember you want to protect your transports, so make sure your fleet, combined with a UK one is enough to deter Germany from attacking your fleets (generally if each side has a carrier with aircraft, a battleship or two and a handful of DD Germany won’t have enough firepower to make it a tasty target to attack). The rest of your IPC should be spent to get yourself 3 rounds of 4-5 TT flowing - one from the US to Gib, one from Gib to Italy, Norway or Europe somewhere, and a third returning from Gib to the US to pick up more units.
Thats a general outline, its not very specific because the US is more of a reactive play type - as you have to react to and anticipate the Axis moves. Once the US is dictating the tempo, the Axis are on their way to losing barring a lucky roll of the dice.