Autopilot has nothing to do with AI assistance. You should probably search for some tutorials (either web pages or videos) for the specific airplane you want to fly in the sim. Different planes have different autopilots (or in some cases, no autopilot) and are controlled differently depending on the plane. (Or via external controls, if you have them).
Generally speaking, an autopilot will be able to engage some sort of lateral mode (either ‘roll’ which just holds the current roll, or ‘heading’ which maintains a specific heading, or ‘nav’/‘lnav’ which follows either your GPS flight plan or a specific radio beacon, depending on configuration) and some sort of vertical mode (‘pitch’ holding current pitch, ‘vs’ holding a specific vertical speed, ‘ias/flc’ maintaining a specific indicated airspeed or mach speed, or ‘vnv’/‘vnav’ which is more complex and usually not properly modeled in the sim right now).
Additionally there’s an ‘approach’ mode which can engage both the lateral and vertical modes when following an ILS or RNAV approach with vertical guidance. You’ll want to look up details on using these properly.
Some planes also have an autothrottle which allows it to maintain a specific speed throughout the entire flight profile, managing the throttle for you. This includes the Citation Longitude, the Airbus A320, and the 747 and 787.