I don't mean to step on the toes of my fellow staff or the other excellent posts in this thread.
FL, I say this without being a Marine, quite ironic perhaps given that this the Marine Corps' birthday, but go into the USMC because you want to be a Marine and everything else is gravy. Within reason, the services have jobs which overlap, are similar, or even more-or-less identical. You're thinking about which race care to drive when you don't even have a learner's permit. Unless you are going for a service-specific job, pick a branch and go from there.
Next, x SF Med's tasker was designed to make you think, not regurgitate info found anywhere. You came to us as a clean slate and he tried to make you fill in some of the blanks. Any idiot can copy and paste, but that isn't learning. The heart of SOF is performing the basics at a high level. Critical thinking and articulation are something that every adult should possess. You're 17 and we could give you a bit of a pass on these two if you weren't so far off the mark.
We've helped I've-lost-track-of-the-number guys and gals in your position make a choice, BUT IT WAS THEIR CHOICE. We helped open a door, we didn't shove them through. Your OP makes it sound like you need a push and we don't do that.
Oh, this?
The question I asked about the Marine Corps and Special Forces was inane (stupid)
We either know synonyms for inane or can look up the definition for ourselves. Id have thought nothing of your usage of the word had you not felt the need to elucidate (explain).
I'll close with: Had you followed x SF Med's intent you would have done your own research, your own thinking, and narrowed down your choices on your own. The simple act of doing the research SHOULD (in theory) have helped you understand your options. At worst, you would be less ignorant but still undecided.
Less CTRL-C, CTRL-V, and more CTRL-N. Go.