Congrats man... Basic isn't hard. It's very physically demanding and mentally trying.
Just make sure you're going in for the right reasons and you keep reminding yourself that it is only temporary.
As for the physical part of it, don't show up just passing the joke of a PT test the recruiters will give you. You want to be somewhat fit when you show up cause you will hit the ground running, no pun intended.
SF is a good path if you really want to do it. Don't do it cause it sounds cool, do it cause you want to be SF. Also in order to apply for SF you will have to contract 11X (Infantry.) If you wash out of the school you will be Infantry. Something to think about.
There are many MOS's in the Army that are great. I'm a 25U, Signal Support, 12B Combat Engineer, and 12C Bridge Engineer. I have been in for 10 years and have deployed twice. I was Air Force for 4 years and switched. I love the Army so much more.
Hooah! and welcome to the family.
PS... Just a hint, while at MEPS and until you grad out of BMT. Don't talk crap about the other services. Remember we are all one team and you have to earn the right to trash talk the flyboys, jarheads, or barrelblowers. lol