If you have 2 in your hand. 5 card hand to start. When you play the first one do you add 5 cards or 4 cards for discarding one in hand? Then I play the 2nd one to increase my hand size to a total of 17or 14 total cards to start first hand? Thanks.

You draw cards until you reach your maximum hand size, not a number of cards equal to your maximum hand size. In this case you would never have more than 5 in hand.

Ok so best to play as last card in hand (if possible), to draw up to 5 cards for a max hand size. Thank you.