Can I use Fidelity/E*Trade/Robinhood/Schwab/TradeStation/InteractiveBrokers/etc. for my options trading instead of TD Ameritrade?

There are many great platforms for trading options, but TD Ameritrade Thinkorswim is the gold standard. Not only does it offer certain important options trading analytics that many brokerages do not offer, but all the ITM lessons & tutorials are based on TD Ameritrade Thinkorswim. So it'll make your life easier to start with Thinkorswim as you learn and then branch out to whichever brokerage you prefer.