The most basic principle in (e)economics is that the price of something will rise if less of it is available or if more people want it. This is called the law of
(s)supply and (d)demand. So if the government just decides to print more money, that money will be worth less, thus causing (i)inflation. The best way to make a (p)profit is to sell something people really want, but not make too much available for sale.
Another basic observation is that people want things they cannot pay for. They might buy things on (c)creditcredit or take out a (l)loan, usually from a bank. The (i)interest (r)rate charged by the lender is what makes banking so profitable. If someone spends more than they make, that is (d)deficit spending. If they make more than they spend, they have a (s)surplus.