Welcome.
Alas manuals are generally written in Mandarin, translated into Urdo by an Italian native speaker, this is then translated into Japanese by a Brit who has been learning Japanese by correspondence course for twenty years, the Japanese manual is then translated into English by a North Korean.
So you are not alone they are all pretty poor if you re not used to the subjects decribed.
Some manufacturers like Korg and Roland have video tutorials that help you get started so watching some of these tutorials specifically on a Korg Pa700 may help since an arranger is an arranger and things are similar but terminology differs.
Alas this is of no help to you.
All I can suggest is to ask questions of us all.