the fool is a weird card in the fact that I don't know if I can fully say if it's the first or not
it's the first in the literal order, yes, but not only from its number, but also from it's meaning, it's more like the one before the first. mostly in the fact that the fool represents the start of a new journey, along with that, freedom from what was once before
what would be more negative readings of the fool include how the fool is commonly depicted as walking excitedly off a cliff without looking down. the fool is brave, and open to new opportunities, yes, but they also may jump into things without logic or without thinking hard enough about what they get themselves into.
the fool also notable has a lot of symbols that might imply that they themselves are the young child in the sun as an adult, if not only as an adolesence. most of these lead from the connection of flowers between the two figures, the fool usually wears a garmit decorated of flowers and sun-like patterns, with holding a flower in their one hand. and also how they have a white dog as the child rides a white horse, along with the sun making a notable appearance in the fool card itself
the significance of this connection is easily debatable, but I would personally interpret as an idea that the child which grows under the love and positive overflow of the sun lends to mature to be expressive and open to new things, presumably as a result of the openness they were able to be given as a child.
this in general should give off the idea that positivity and love are important to growing with maturity and opening one's self to new ideas and experiences
also, I made the fool a girl here, and the sun kid is still a boy, so now the fool is transfem thanks to me, yeah