What electives should I take if I want to be a commercial pilot for a big company like Delta, AA, etc. somewhere in the future?

Airlines typically don't place too much weight on the type of degree other than the fact that you have one. I would get a degree in a field that you are truly interested in. You never know if you decide to change careers (which I did) or if a medical issue prevents you from flying.

Hello Jack. Its great that you are in 8th grade and already know what you want to do in the future, huge props for that! Airlines really look for how much flight time and what type of ratings you have. College and GPA may not play a factor at first. I know plenty of pilots that go basic academic thru school and college just to get a college degree and leave plenty of time and money for flying. Don't get me wrong, a good education will always help you in the end, but as a pilot you are not going to need advanced calculus and algebra. I have never heard of an interview that asked what was your GPA. If anything, I may recommend business courses and maybe some psychology classes. As a pilot you will interact with passengers, and know how they act and think can help in situations. Eventually, like anything else that you are going to do every day over and over again, piloting may start to loose its appeal. Advancing higher will require a college degree, and having a business degree will help put you in management. Its always good to have something to fall back on. Remember that airline pilots have to pass a rigorous physical every 6 months. As you get older and your health and family life changes, you want to have that back up.
For now, I would recommend that you find a flight school nearby and start flying. Have your parents help you look for financing. Flying is expensive and you need lots of it. Take out a loan and negotiate with the school. Get your private pilot license and start working on your IFR rating and your CFI. CFI (certified flight instructor), as you start teaching others, you are building time and experience, and getting paid for it. In the same time as you are around an airport, start to network, get to know people and let then get to know you. Good jobs come from who you know. Flight training will give you what you need to be a pilot
Military is another option, but with all these drones and space equipment its getting harder. Most military pilots come from the military academies. If this is something that interests you, start preparing for the SATs, and join the Civil Air Patrol or the Sea Cadets. I believe the Academies will not consider anyone with an SAT score lower that a 1200. There is ROTC and you can also enlist, but those are not always a sure thing.
Hope this helps, and good luck. Keep flying, your hard work will eventually be rewarded.

Jack,

In order to be a pilot for Delta or American you will need a college degree to be competitive. Therefore high school grades are important. Besides taking your required courses, I recommend taking the electives that are most interesting to YOU, Not only will taking classes you like result in better grades but it will help you discover where your true interests are.

Flying related classes that may interest you are geography, weather, aerodynamics, physics, navigation etc. You could also look for a flying ground school and perhaps a summer job at an airport or FBO. Of course, flying lessons will start you down the road to an aviation career and organizations like AOPA and the Civil Air Patrol have education resources for kids your age.

As for the military, it is a great way to go that will give you the best training while you earn a salary. However, I would only suggest the military if serving your country and flying military aircraft while conducting military operations really interests you. Don't do it just to get an airline job because military duty requires a commitment and lifestyle that isn't for everyone.

Good luck to you. I am sure you will accomplish anything you want if you give it your best effort.

Honestly I would take electives that are easy and help you maintain your GPA. To be a commercial pilot no one will ever ask you what electives you took. All interviews will be around commercial pilot procedures and your log book experience. Having a strong math and aeronautics background in important. I graduated with aeronautics degree and had to work hard for it. When I went to flight school I realized that I could have taken any major ( even culinary) and still end up in same place. Save your energy and money for flight school. While in college work on a backup plan. If you don't become a pilot what is your plan B? If your eyesight fails what's you plan B? If the technology effects the airline industry to have autonomous planes then what's your plan B? Having a strong business or finance background will allow you to switch industry if you need to fall back on it. Aviation industry goes thru ups and downs and you want to make sure you are standing either way.

If you’re looking for specific classes to take, I would recommend trigonometry, earth science, and a basic physics course somehwere along the way, just so that you have some exposure to the concepts you will need to master in aviation: navigation, meteorology, aerodynamics, etc. When I was a college flight instructor, I could always tell which of my students had taken these courses in high school, and which ones hadn’t.

Beyond that, just take classes that interest you, and focus on earning good grades.

Also, I’d recommend that you find a local flight instructor, flight school, or flying club, and take an introductory flight lesson in a small airplane. They typically run about $100. Either it won’t meet your expectations, or you’ll get hooked and you’ll know for sure that it’s what you really want to do. Either way, it’s a good investment.