What important formulas should I know before investing in stocks?

If you want to invest in stocks first you want mantally prepare for big losses.i saw that there are so many people invest in stock market with there daily routine money. So first of all if you have some extra money in your saving bank account,and if this money losses you doesn't matter after than you and your money are ready for invest.
1.don’t irritate if you loss money.
2. I saw that many people buy shares when the share price gones higher and market experts say that the price of the share gone higher in a few days,weeks and months. Don't trust on this experts because the price of the shares is already higher and it no longer gones higher so don't buy shares on high price.
3.never enter in stock market if stockmarket is High.
4.never do intraday.world best invester mr.warran buffet say that if you want to success in stock market never do intraday..
5.always recommend that buy stocks in low price when all investors sell there stocks. If you follow that line after that you get a big profit in the market.
6.keep stocks for long term.
7.don’t get irritate when the price is fluctuate.don’t sell your stock without analysis that this is right time to sell.
8.always sell your stock if you have two reasons (1)if you have some emergency.
(2)if your reason for invest your money for a perticular company is finished.
9. Always first of all analysis all things about the company and research about there future plans and there past also.For research about that saw the company annual report. To download annual report you want to go with site Stock screening and analysis tool .
10.don’t trade in for short time like 2–3 days to 2–3 months always invest for minimum 1 year for the success incase you don't have an emergency.
Thanks,for read my answer..