shifting questions with 5r55e

[charlie brown]

i just cant seemed to understand this trans. if i put it in 1st, sometimes it starts in 1st or sometimes in 2nd. the trans only has manual shift spots for 3 foreword gears but is a 5 speed. i know that the 5th is overdrive and i have a button installed for the "converter lock out" which i think also has something to due with the 1st gear thing.
It will down shift fine.

any help with that would be great. it is a 5r55e trans and i just installed the transgo kit.