what is first true leaf?

i cant seem to find anything to clearly define what the first true leaf is on a cannabis plant. is it the single blade leaf that sprouts above the cotyledons? or is it the first set of 3 leaves that sprout above the single ones?
also as far as counting nodes would i count the single blade leaves into the total amount?

the 2 little ones are its seed leaves, they are there first so are its "first true leaf" but as it gets bigger they go brown and fall off, so no I wouldent count it as a node.

The first set of single jagged leaves is the first set. Although, you don't usually get a branch to sprout off that node. The first set of 3 is the first node that can sprout a branch. The single set normally falls off about mid veg, so it's the first, not the first permanant. Pick your poison.

so the first set of true leaves should be considered one with 3 blades or more?

yes

the first true leaves emerge after the cotyledons. they are serrated and usually have one or more lobes and have an opposite leaf arrangement. as the plant grows the lobes increase to seven or nine or even more.