Let's figure out how to preserve the money we earn without wasting it away with inflation. When a dollar or other currency loses its purchasing power, we call it inflation. 100$ dollars you saved 20 years ago can buy you 40% fewer goods. Instead of having ten apples twenty years ago, you saved money, and now you can only get six apples with these dollars.
The most popular way of measuring yearly inflation in the US is the consumer price index which is 7.75% this month. It measures the overall change in consumer prices based on a representative basket of goods and services over time. Some things go in price more, while others less, and CPI will measure them all to produce an average number.
We can already see that inflection will affect people differently based on their spending patterns. For example, in the past year, the biggest mover was transportation which changed by 16% . If you work remotely and don't commute or travel much, it won't have big impact on you. Another item of high inflation is housing, so if you rent a place, you will feel its impact more. But some random goods didn't go in price much, for example, bananas and shoes. So the first and most obvious thing we can do is to be aware of prices on different things and try to spend less on things that are growing in price faster than others.
Accepting that cash loses its value over time leads us to a simple mental model that we need to save a reasonable amount of money while investing the surplus to at least preserve our income. The amount of savings would be different from person to person. For example, I'm trying to save for one year of minimalistic living in case I lose my job, together with an emergency fund in case of health problems.
The easiest and the most obvious way to invest is to buy stocks. Since we are not professional investors, the best approach would be to dollar-cost-average in index funds, basically putting the same amount of money into a preselected basket of stocks like the S&P 500 every month. Some years stock market will go up, and some years down. It might be risky in the short term, but if we are playing the long-term game, there is less chance of losing. An investment made in S&P500 in 1900 would bit inflation by 6.5%. But an investment made in the growth period and then turned into cash in a recession would've been a loss.
Another obvious choice for protecting against is real estate. In developed western countries, it's easy since you can get a 30-years mortgage with a low fixed rate that is less than inflation. Developing countries would have higher interest rates on a mortgage and lower purchasing power of residents, so if you have cash, you can have an advantage there. While real estate grows in price anyway, you can earn extra from tenants or businesses in the case of commercial real estate.
Once we realize that it's possible to bit inflation with either real estate, stocks, or other financial instruments, we should focus on the most important one - investing in ourselves and our ability to earn more money. It could be learning programming to become a software engineer, working less at a day job to put more effort into a business, or moving to a place where you'll have more opportunities.