The road to becoming a BCBA can be a really tough road. There is schooling, supervision, and other hurdles. However, it is worth it and I am pleasantly surprised about some things I have learned becoming a BCBA.
Teaching a child to request (aka mand) is one of the first programs we teach in applied behavior analysis (ABA) because there is motivation to communicate. Mands are great to teach when replacing (or reducing) problem behavior. The great thing about teaching your child to request is you have plenty of opportunities to practice "mand training" at home, in your own routines.