We need more information, to find out just where you have gotten to. First, we assume you have downloaded and installed RE. Further, we assume you have 'executed' RE, so you have RE window(s) displayed on your monitor. Good so far?
Have you figured out how to create and populate a watchlist? (Just a few symbols to start with, perhaps 6?)
Have you figured out how to configure Yahoo downloading of OHLCV for the symbols in your watchlist?
That's a start . . .