Candle sticks are 1 of 5 elements (with indicators being a support tool) used to understand the price action on a chart. As you gathered, the others are 2) Support and resistance 3) Trends 4) Moving Averages 5) Fibonacci levels 6) being divergenceconvergence and 7) the indicators tools but are not part of the price action.
It is very important you understand candle sticks and their many possible combination, for candle stick and their associated grouping can contribute to determine if its a bullish or bearish price action to follow. However its not as important to memorize these formations but more important for you to understand why they are bullish or bearish by looking at them, and you can always refer to your reference sheet to gather if its a strong, reliable or weak formation.
To conclude, candle sticks help tell you what is happening along with context of where there is selling or buying pressure. They should not be used in isolation to generate trading signals. There are too many other factors that impact on price. But candlesticks are helpful, when used in conjunction with volume and volatility with major behaviors with support, resistance and trendline breaks.