Would like to know about handicap seating , is there anything special that has to be done for handicap seating ?

No. Just order a handicapped seat. There are fees and ways to avoid them. Go to box office rather than online to avoid fees.

There are special areas set aside for people who use wheelchairs. They are good at accommodating everyone from what I've witnessed. If information isn't freely given while trying to purchase tickets for an event, I'd suggest calling the venue to make sure the seats you're looking at will work best for you.