Theoretically, price action trading is simple. Simplified, you can trade ranges and trends. In reality, it’s often not that easy, and there appear ranges and trends at the same time. The true target is to see what most of the other traders see. But let me start from the beginning:
Trends
A trend appears if prices mainly go in one direction. Trends can go up or down. They vary in duration, price levels, pullbacks, and so on. If you want to trade a trend, you should trade with the trend (the trend is your friend). So uptrend -> go long, downtrend -> go short.
Range
A range appears if prices stay between two price levels, so they bounce up and down. The theory here is to go short at the higher price level and to go long at the lower price level.
This is the very basic theory behind trends and ranges. I want to keep the information in small pieces, so this should be sufficient for the begin. For more detailed information, you can refer to the additional articles on trends and ranges.