These days, I see many people investing in companies without even knowing what it does. 
If you are a trader that analyses charts, follows momentum, or look at other technical factors, sure. But for the majority of us, investing in what we don't know will lead to disaster.
"Stick to your circle of competence" - Warren Buffett
The worst is, these people are influenced by emotions and panic sell when they see a red day.
What happens when you know what you're doing, and what you're investing in?
You won't be as affected emotionally and can make rational decisions. Since you know and believe in what you are investing in, emotions won't get the better of you when you see huge fluctuations in stock prices.
These are the basics to selecting companies:
1. Understand what the company does(your circle of competence)
2. How does the company make money and can they keep growing long term?
3. Use valuation methods such as P/E ratio, DCF, P/S ratio etc. to estimate the intrinsic value of the company
4. Is management of the company good, or ridden with scandals?
5. Are you comfortable holding this stock long term even if it goes down?
Being patient can be tough sometimes. But think about it this way - you don't have to do much once you decided on a company. If you done your research and fundamental analysis correctly, you don't have to worry about it.
It is only when something has fundamentally changed about a company that you need to evaluate it again.
Good luck!

Do you always seem to pick a stock and it suddenly plummets from there? You may think you have some curse on you picking the wrong stocks at the highest possible price.
Here's some helpful tips to choose the right stocks!
1. Understanding the Company
Do you understand what the company you're looking at is doing? Their business model? Their pros and cons? If you don't, investing in a company you don't understand can be disastrous.
2. Look at the Financials
After you've found a company that has a good business model and one that you understand, it's time to look at their financials.
You can find them with platforms such as Moomoo.
Look out for their revenue, P/E ratio, Profit Margin, and so on!
3. Invest...Long term
Once the company checks all your boxes, slowly add to your position (not all at once!). Hold it for the long term or until something fundamental about the business changes.
If you don't want to worry, do the research, analyze companies and fundamentals, I suggest buying an ETF that tracks an index. For example, tracks S&P 500, Dow Jones, and so on.
Historical data shows you'll get ~8-10% return per year passively if you invest in index funds.
Best of luck for investing!

This rule will hopefully be passed down generations to come.
Investing is NOT Gambling.
Investing requires you to find out about the company's background, financial statements, competitive moat etc. You may also invest into an index with a proven track record such as the S&P 500.
Buying into a company without even knowing what it does is a big NO.
Unless you're a trader following technicals and trends, investing requires you to buy into a company for the long term.
Trading is also not equals to investing. Moomoo and other sources provides educational content and courses for you to excel as a trader. Do not go in blind!
Hope this helps. May you be financially free!...