Looking over your parts list things seem pretty reasonable but if you can spare the licensing fee it's worth getting an account on ecalc.ch to plug in all your numbers and see what it says about flight time and load on the system (will show an in the red indicator and warnings if anything is going to cause issues and can save time/money on parts and give you some idea of the flight time you can expect given a particular battery etc. etc.)
Also being a first time thing I strongly recommend you build something smaller, a 3" or a 5" prop (more common) based build (or 250mm frame size) is going to be way more common to find and so cheaper and at the 3" size they are very durable so can get in a lot of crashes while learning if planning to fly manually at all (my favorite way). If you are only interested in the GPS based flight I'd suggest checking out iNav since it is compatible with more modern flight controllers, I don't have much of a pulse on the APM or pixhawk side of things so not sure how much active development there is on either of those (think more on pixhawk but know for sure betaflight and inav are supported on most modern FCs typically based around the STM32F4 or F7 MCU).
A smaller build is easier to work on, will make sure you have all the basics right first in terms of hooking up receiver and doing TX/RX binding etc. If desired can get an FC that supports the GPS to test that out a bit in betaflight or with iNav as well (Kakute F7 board and I think the 722 based boards both support this, just look for I2C input for compass and RX/TX available for GPS data input).
A bigger build will get more flight time in general but also much harder to work on and tune the PIDs and other details that will be hard to grasp as a beginner.