Weh beach starting , front foot is easier , but you can do both .
but front foot helps from a tendecy to be heading/ rounding up immedialtey by putting force on more to the front of the board.
BUt Front foot can also lead to a catapult if your not carefull.
I using the back foot for heavy heavy winds ( ie 4.5 condtions ) and even put it in the strap, to keep me in control and from a catapult back.
Also beachstarting with the back foot trains you to do the WATERSTART POSITION