1st have you got your emergency cash stored up? Can you tahan if you are out of job for say 2 years? These are the basic.
2nd determine what kind of investors you are.
Dividend investing, dividend growth investing (buying companies with increasing dividend), value investing (buy something you think oversold and not at real value and wait for price to pick up), growth investor (buy growing companies usually small companies and hope to profit big time), player (treat the stock market like a casino), trader?
Are you a local or international investor?
3rd what will you do if a stock drops 30% in value? What are you going to do?
4th Will you employ leverage (take loan from brokerage and buy using borrowed money)?

After answering those questions yourself (I don't need the answer, is for yourself)
Here are some resources for you or read.
https://dividendmagic.com.my/stock-investment-malaysia/ (dividend investing slow lime tortoise for Malaysian markets)
http://singaporeanstocksinvestor.blogspot.com/?m=1
https://www.mrtakoescapes.com/farmers-hunte...l-independence/
https://www.mrfreeat33.com/my-story/

Recommended books
https://www.sgbudgetbabe.com/2017/07/recomm...inance.html?m=1
https://www.mrtakoescapes.com/the-keys-to-w...hanged-my-life/
http://singaporeanstocksinvestor.blogspot....and-ta.html?m=1

Avoid stock market courses. Most of the time they do more harm than good (sell you empty stuff/useless). Read financial blogs and books.

Know the company you want to buy in. Don't simply buy.

Not true. If you are a trader then yes. Not important.

Gambling I'd you don't know what you are doing and buy hoping price all shoot up. High High mentality.

They are one of the last people I will learn from. Remover only want to make you buy and sell. They make commision if you frequently buy and sell.