Is there a good article that explains how this all works?
Really only necessary if you need to be able to run some calculations for design work.
To get a general overview idea, think ...
(a) structure exists .. and we are looking more at the region around and outside the engine itself but still subject to airflow due to the engine.
(b) air is flowing over the structure due to the engine's good work and the aircraft's flight speed
(c) air has pressure which varies with local speed
(d) hence the air over different bits of structure will have slightly different pressure
(e) for each little bit of structure, the force associated with the air pressure acts normal (perpendicular) to the little bit of structure
(f) resolve the little bits of force into whatever directions are of interest (ie typically forward and aftwards are what we are after)
(g) integrate (add up) all the little bits of contributing force
(h) end result gives a nett thrust or drag
(i) the thrust or drag varies through the engine so, in some regions, we are getting useful thrust (nacelle and nozzle) while, in others, it's all drag.
One needs to keep in mind that this is the province of the aeroplane designers rather than the engine folk. The engine has to hang inside some structure and have suitable airflow conditions presented at the front and somewhere for the hot bits to get out at the back.
A similar argument can be structured for what happens inside the engine proper.