Pro Audio just purchased and have a question about my Behringer XR18 Mixer (Digital)


I just bought my dream equipment at the ripe old age of 63 years.  Two QSC 12.2, One QSC 10.2,  Behringer Digital Mixer with IPad app, Shure ULXD Receiver, KSM8 Transmitter. I have enough to work with for now but will be adding and new power condenser, SKB rack in addition to the one I have, accessories to attach my antennas on the front of my receiver in the rack, and a maxed out 16 in Mac Book Pro custom with 2 Terabye SSD.  Ok so I figured out how to connect things to my mixer but now I need to know how to connect my computer to the mixer.  I'm thinking it would go in the USB but how do I fined a cable long enough to reach?  I use my living room and formal dining room for my equipment.  I am only doing this for me to sing at home and I haven't purchased any karaoke songs yet because I keep getting so many opinions about it.  I really like Sound Choice but, That's not happening.  Also once I connect the laptop, do I send my effects in the Behringer app to my mic channel on the mixer?  Also, If I were to purchase Antares Auto Correct or one of their software programs, can I use the effects in live singing or just recording?  It's a huge learning curve for me.  Thanks!