Welcome to HS! Freshman year was really fun for me, you’ll enjoy it. I’m only a year ahead of you, but I think I can give you some advice.
I was involved in DECA, and it’s super helpful even if you don’t want to go into business (I don’t), it just helped me a lot with job interviews etc, people are always impressed and it helped my confidence a lot. I never got to join debate team but you should if you’re interested in it - i regret not doing it. Join ECs based on which middle school classes you enjoyed, and career interests. Also, maybe think about summer internships depending on your age. There are a lot of internships put out by the US government in every field (it’s called Pathways) but you have to be 16. I’m really interested in doing one once I’m old enough. But you can find one at your local university or some company.
Just enjoy freshman year, but don’t feel like it’s too early to look ahead. If you need more advice on freshman year/classes you’re taking in freshman year, you can PM me anytime!