I am on the go frequently and am asked to make short (and long) presentations. I have become very comfortable with Microsoft PowerPoint and built up a repertoire of reusable content that I update. I know those who have all their devices in the Apple world like to use Keynote which has its own set of benefits.
If you want to display your presentation on an external device (such as a monitor, TV, or projector), you need to purchase a Lightning Digital AV Adapter (AV = Audio Visual). This adapter plugs into your modern iPhone or iPad device through the lightning port and provides 2 connections: an HDMI connection which is used to connect to an external display and a lightning port which can be used to charge your device while in use during the presentation.