I'm getting the garden ready, seeds are started.

I'd like to do just organic fertilizer this year. It's not easy to
find, Miracle Grow has one, as did one other brand that I don't
recognize. These seem to be have little to no K and P and are almost all N.

Since I'm a city boy, what should I be looking for? I'm just growing
the usual "garden variety" veggies. Tomatoes, assorted cucurbits and a
few blueberries and a peach.

Wally World has a product called Earthgro Organic Humus and Manure,
that's .05 .05 .05 at $1.50 for 40 pound bag. Consistency looks good in
that it doesn't seem to have much, if any, wood in it. Soil (Atlanta Ga)
is still clayey (particularly if I go down a foot). I've used up the mulch.

Should I amend heavily with this? Will I need more fertilizer later?
To start with?

Jeff