Hey,

•Aerospace engineering is the primary field of engineering concerned with the development of spacecraft and aircrafts. 
It has two major branches -:
•Aeronautical engineering
•Astronautical engineering

Yes, aeronautical engineering is a branch of aerospace engineering but both are different.

•Aerospace engineering is a broader subject than aeronautical engineering. 
It includes space research and designing of spacecraft and rockets.

•Aeronautical engineering includes the designing and development of aircrafts.

Here you'll find everything about aerospace engineering including eligibility criteria, scope, course subjects-:
https://www.careers360.com/aerospace-engineering-course

And click here for aeronautical engineering-:
https://www.careers360.com/aeronautical-engineering-course

So, you can pursue engineering in either of these two streams.

All the best!