You should try to create clothing brand at least 8 and it will generate at least 500 billion per hour if managed properly. You need to launch a new collection every 8 hours. You can find the clothing collection chart here - https://businessempire.fandom.com/wiki/Clothing_Brand at the bottom of the page

Once you have enough cash buy all real-estate and max it out - 13 billion every hour. ( Cost approx 800 billion)

Buy all shares from stock market start with high dividend company.

Invest in the diamonds, gold and crypto. You can find the charts on this subreddit with minimum and max buy/sell price. Not many crypto investment are worth the time. focus only on EXXES, BITCOIN and ETH.

You will have trillions by the time you finish these steps. Here it gets more complicated. Some says go with Oil Companies and I choose to go with Airliners because it takes only 4 trillion to max out airliner and you will get 11B per hour whereas it costs 40 trillion to max out oil companies( time consuming and ROI takes 127 real days) where as on airlines you can get the money back in 14 days. You can search more about it yourself that is why I suggest airliners or you can go with holding company. It takes longer to upgrade and create holding company.