Where and how can you invest?
There are many ways to invest your money, but as a beginner investor, I would limit myself to a maximum of four investment categories:

Cash
Liquid assets such as savings accounts and short-term bonds.

Shares
A share is a piece of ownership in a company.
As a shareholder, you participate in the capital of a listed company.
A share entitles you to a portion of the profits (dividends) and a chance of capital appreciation.

Bonds
Debt securities, a portion of a loan from a country, a government institution, or a company.
A bond has a fixed term (5 to 30 years).
A fixed or variable interest rate (the coupon) is paid annually, and at the end of the term, the bond is redeemed (VEB).

Real Estate
Real estate such as a vacation home or office that you purchase for rental income and capital appreciation.

Which companies you invest in is something you need to be confident in; you might want to look around in your own environment or employment situation.

For example, someone in construction or a DIY store often comes into contact with sales representatives and other companies, so why not invest in a company like

Bosch or Stanley?

Why invest?
The main reason to start investing is that a well-diversified portfolio of stocks and bonds has yielded much more than a savings account.
Investors thus accumulate much greater wealth than savers.

Especially now that savings interest rates are historically low, it can be worthwhile to start investing.
Inflation is higher than savings interest rates, which means the purchasing power of your money is declining.

Historical returns don't guarantee future performance, but they do provide an indication.

US stocks have returned 10.2% annually over the past 100 years, and bonds 6% (Vanguard).
European stocks have returned over 8% annually since 1987 (MSCI Europe).

I think an 8% to 10% return on stocks is realistic for the coming decades as well.

Below, you can see that the 10-year government bond yield is very low.
Corporate bond yields are generally higher because they are already considered riskier than government bonds.

Is investing risky?
There are certainly risks associated with investing in stocks and bonds, but you can significantly mitigate these risks with a well-diversified portfolio and

a long investment horizon.

A 10-year investment horizon is the minimum if you want to invest in stocks.

Keep in mind that stock returns fluctuate significantly (are volatile).
In 25 of the 92 years, the US stock market suffered a loss.
In the worst year, 1931, it even returned -43.1%. On the other hand, in the best year, 1933, a return of 54.2% was achieved (Vanguard).

As a stock investor, you must therefore be able to tolerate significant fluctuations in annual returns.
But if your investment horizon is longer, the prospects become much better.

Over a 10-year period, the worst period yielded -5.92% per year. The best period was 19.96% per year (Shiller data).

For a period of 15 years, the return of the US stock market (S&P 500) was consistently positive (Malkiel, p. 353, 1950-2013).
Over a 20-year period, investors achieved an annual return of at least 6.46% and a maximum of 17.99%.

I am optimistic about the future and expect a long-term stock return of 8% to 10% per year for well-diversified stock portfolios.

A Broker?

These days, there are numerous apps that allow you to buy stocks, eliminating the need to visit a bank.