Jack are the ones that go into nearly every input along the top of your mixer (apart from the 2 black ones on the top left which are XLR). Phono are the red and white ones on the r/h side at the top. XLR are better: XLR typically gives you a 'balanced' connection, whereas the Jack connection is unbalanced. ... For a high signal level instrument, like a guitar, this is often not a problem, but for a low level signal like a microphone it could significantly degrade the sound quality, so balanced connections are used.
You might wish to look at this: https://www.displays2go.com/Article/PA-System-Components-Microphones-Mixers-Amplifiers-Loudspeakers-12 or similar or maybe even go to site dedicated to PA systems for more detailed information?