Okey that isn’t that hard:
on join:
send “ Welcome %player%!
give player iron helmet
give player iron leggings
give player iron chestplate
give player iron boots
give player iron axe
give player iron pickaxe
give player golden sword
give player 10 steak
give player 4 golden apple
or
on first join:
send “ Welcome %player%!
give player iron helmet
give player iron leggings
give player iron chestplate
give player iron boots
give player iron axe
give player iron pickaxe
give player golden sword
give player 10 steak
give player 4 golden apple