How do I choose a call option’s expiry date, strike price to speculate in?

If you want to use Calls to your advantage with a higher chance on success than yolo-ing on weekly calls, try LEAPs on stocks which you have high conviction on. This is a strategy that many growth investors use. Usually they'll select the furthest DTE to maximise the chance of your LEAPs being ITM.

Choose a longer expiry date, near ones expensive premium and higher decay. STrike price choose something higher than the current price