if you have 1 billion dollars, what will you do with it, and why do you want to buy some clothes or a car in the first place?
you've got so much money that you can buy almost anything, which is really expensive

split it into 500m

invest 250m into something stable, and leave it for my family or kids in the future
invest 250m into something for myself so i'd have some to back up from

spend remaining money to finish our current home, buy a new one and all the typical stuff
and with what is left, id invest some of it into starting my own business, and ofc have fun

In reality, i'll do just as planned, but differently i would give millions of dollars to animals instead of spending them all on a nice mansion for myself extinction, the homeless, charitable giving, and aiding those in need around the world

split it, spend it, invest it.