At start of player one turn ,he rolls all three dice twice. Is correct sequence roll 1st set of dice then 2nd set then resolve both event rolls then distribute resources, or , roll 1st set of dice then distribute resources then roll 2nd set of dice then distribute those resources.
Looking at rules here it says
As is customary, each player rolls the dice two times when beginning his turn; for this, all three dice from C&K are used (white die / red die / Event Die). If the second dice roll gives the same result as the first roll, the second roll is repeated – but only the two number dice are used, without the Event Die. The Event Die result is resolved immediately. Therefore, even though you may have to roll the number dice more than two times, the number of Event Die rolls is limited to two.
So if the second roll matched the first you carry out the event die and resolve again. If you hadn't already fully resolved the first roll you would then be resolving the 2nd event before the 1st due the 'immediately' instruction which feels odd to do unless explicitly told too.
The basic game rules here state :-
Each player who has a settlement on an intersection that borders a terrain hex marked with the number rolled receives 1 Resource Card of the hex’s type. For an example see resource production
As the original rules say you get resources if you have a settlement on intersection rolled then I would do that straight away and resolve the even. and then make second roll and resolve that.
Also there is a video demo of the rules here and go to 2:40 you will see the demonstrate roll 1st, resolve 1st, roll 2nd, resolve 2nd.