Generally speaking you will find a bridge rectifier, then DC bus caps, then a 3-phase / 6-switch (IGBT) bridge. Nothing much else needed on the power circuit.

With single phase 240V input, only 4 of the 6 rectifier diodes get used but as I said, most VFDs don't check for a missing phase. The manual may define a slight derating when you use single phase instead of three phase input but the rectifiers are pretty robust and unlikely to be an issue for intermittent / light hobby use. The DC bus is going to be around 340Vdc and obviously you can't generate an AC voltage that exceeds 240Vac from that, hence you normally need to connect your 3-phase motor in delta if it's a 240/415 star/delta machine.

On higher power VFDs (>6kW or so), the bridge rectifier will become an active PFC ie another 6 IGBTs instead of rectifiers. And they may then be bidirectional ie can regenerate back into the mains during overrun.

Some VFDs come with built-in EMC filters but that's the exception rather than the rule. It's a good idea to fit one if you can.