The best way for you to be useful to the world is to be a good child to your parents, spouse to your partner, parent to your child, and friend to your friends.

The best way for you to be useful to the world is to be a good child to your parents, spouse to your partner, parent to your child, and friend to your friends. You don't have to embark on some quixotic 'save the world' quest to be useful - just taking care of the basics is huge. Many many many people mess this up, including many of the ones who think they're off saving the world. Right now you're trying to learn skills that will make you economically secure - which will make it far easier for you to be a good child to your parents, spouse to your partner, parent to your child, and friend to your friends. In other words, you're doing exactly the right thing. Carry on with it.