programming is such a wide field, that there too many jobs to be able to determine whether programming is stressful or specific advice for a career.
for example videogame development is extremely stressful with 80 hour weeks being not uncommon.
while maintaining a database can be quite relaxed and allows for much free time and time for other projects.
what I can tell you is that programming is a practice based skill. also no matter how easy your first programs are, you need to document everything because picking up the habit once you already know how to write code is far more difficult than from the start.
there are many videos on youtube that teach programming basics. I'd start with java (not javascript) or c++ (I personally started with java then in grade 10 in school i did turing then java again in grade 11, 12 and first 2 years of college) because they are great languages to start on. (they teach pure programming logic fairly well) just remember that your first programming classes are supposed to be made to teach you how to program in general not in one specific language. this means that making the switch from one language to another will be very easy and quick to do. you can learn a lot more on your own than what you can do in a high school class however the structured method of high school and first semester college classes means that you will get all the basics covered.
overall programming is fairly rewarding if you do your stuff right. while it can be quite stressful at times, the rewarding feeling you get when your programs finally work is amazing.
also remember that programming for a purpose is much more rewarding than programming just for the sake of learning a new keyword, see if you can join a robotics team at your school or a nearby school that has one. robotics programming (mostly done in java) will teach you about classes and object. external libraries, and how to get code working fast. from my high school career I really enjoyed programming on the robotics team and found it to be a much better learning experience than any class I had taken prior. (just a basic program to control a robot with 2 joysticks in tank drive mode will teach you to use external libraries, classes and object, IFs, Whiles, and some boolean logic).