You should learn how analyse the trendline, and identify 2 basic things:
This is not an easy skill, but just these two things alone can help you figure out when to buy and when to sell.
As a general rule, you sell when you've hit a resistance line and buy when you've hit a support line. (the problem is you have to identify them and you can easily mix them up in real situations, especially because, for example, a resistance line can be breached from time to time)
As an example of this, check this image:
https://www.investtech.com/images/help/indicator/supResBuySell.000.png
That is a pretty huge skill which is for those who have been able to learn with some experience and know how to really trade effectively. Trend lines with price actions are always good and that is always the best way to trade short term anyway. Long term is always different in a way, but trend lines are always very good as well. Trend lines will always help you to know when a trend is changing most of the time and I have done this several times to get the best of the market.- support levels
- resistance levels
This is not an easy skill, but just these two things alone can help you figure out when to buy and when to sell.
As a general rule, you sell when you've hit a resistance line and buy when you've hit a support line. (the problem is you have to identify them and you can easily mix them up in real situations, especially because, for example, a resistance line can be breached from time to time)
As an example of this, check this image:
https://www.investtech.com/images/help/indicator/supResBuySell.000.png
Try to join some telegramm groups dedicated to trading topic, there are many skilled guys there, who can advice and suggest you pne
There could be many groups for sharing their predictions but if you think deeper why they need to share by consuming their precious times. I see many groups are sharing free tips for the purpose of making big crowd participation for their bumping. Nothing else. 
