play in sandbox mode look for it in settings

If you want a ton of money with normal mode, you could try using Cheat Engine.

or you can download the mclaren f1 from the workshop you can find it in junkyard and when its fully restored you sell it for 12 miilion i did that and now i have 60 million without cheating

As EL Balls says. The FI or better yet FI GT will score you big cash once restored. I sold my last FI GT for 18 million. I found mine in the junkyard

create a new normal game with the profile name cms2018promo
you will start off max level, with tons of money, and a fully upgraded garage.