This question is probably no clear, and I can’t figure out how to word it.
So,
Do I need a letter of recommendation from every single extra curricular in order for them to be valid, or is a letter of recommendation from an internship or one of my golf coaches and mentioning of the others from my Guidance counsellor enough?
No. Admissions isn’t going to read 10 letters of recommendation. I am not sure how it works with homeschooled kids, but the general rule of thumb is 2 teachers, guidance counselor, and maybe an extra letter from whoever. But any more would be overwhelming to read for admissions officers.
Just list your activities in the designated spot on your application. You don’t need separate proof you did them.
Some schools do audit EC’s so make sure you can document the activities listed if necessary. It does not have to be an LOR but anything that can substantiate you participated in an