always start here where the line is wrapped over the main line. back up the spool and pull it out some then gently pull forward on the main line. rinse and repeat.
there is an easier way but most people will probably crease the line and it will break on the next fish you hang.
Spin backwards find the spot un kink it do it again until you find it all. Dad started us on baitcasters at 8 or so. I spent many a whole fishing trips as a kid getting my birds nest out. But that was part of learning.