TradingView
Industry-standard charting platform. Free tier works; paid unlocks more timeframes and indicators.
Best chart rendering and drawing tools. Free is enough to learn; Pro adds a second TF on one chart. Alerts, indicators, and annotations all live here. Essential for serious chart analysis.
Related
Learn to actually use TradingView.
Definitions are the easy part. The free first five modules put this on a real chart and make you do the work. No card required.