Indoor to outdoor?

As much info as I can find, I cant seem to figure out how to best assist my plants with their transition to the outdoors. They've only been growing for 6 days under 4750 lumens pr sq foot. Well into second set of leaves but for 3" tall and 3" wide, noticeably thin stalks.
Im in the North East so Im obviously way behind the season, but am I really as screwed as I feel? What shoulD I aim to yield?

Does anyone have experience with this type of situation?
Any and all ideas/suggestions may help me get back on track?

Vague I know, but Im stuck:(