What I should do, or who I should talk to, if I’d like to try out another branch like Air Force or Navy?

You ETS, take your DD214 to the recruiter of the branch you want and hope they're taking prior service

I don't have your answer, but, I do know that the Air Force doesn't take prior services very easily. I think the Navy is a little more open than AF but is still a little rough on it. If I were you I would try contacting a recruiter for each branch and ask about it from them and gauge your opportunity with them before you make your decision. That way you dont ETS and then regret it but can at least say you weighed your options before making a decision.

Stay Army if your current plans are to make a career. Grass may not be greener in another her branch. After you complete your tour with the Army, you would be considered prior service. This could be difficult for you...
My advice, stay Army...hooah!!

Oh, and be careful of any recruiter who hands you a conditional release to get filled out. That doesn't apply to active duty Army enlisted. People will tell you all day that it's possible and "they know a guy who did it", but at the end of the day, you still have to ETS normally from the Army. There is no early release from your contract and there is no such thing as transferring to another branch.

Like previous comments have stated, you can't transfer prior to your active duty ETS obligation. But start by locating a prior service recruiter in your area. Typically, a regular recruiter can get you in touch. Make sure you ask a lot of questions before you make the jump. Service, expectations, and promotion systems, are not the same across the board. You have to figure out the right questions to ask. Recruiters from different services won't know how to help you transition to a new system.

SPC Joseph B. That can be difficult. Not all services allow prior service to enlist, especially from other services. I guess they feel you might be tainted in some way. You would really want to check a few things:
1. Is the service you are considering even taking prior service members from another service. (If not, you might ETS only to find no way back in)
2. Will you be able to retain your pay grade. (You don't want to go backwards in rank/pay)
3. Do you want to repeat Basic Training again. (Not all services will ask this, but.......you should ask if you will have to go through this with the new service)
3. Do you just want to change your job? (You could re-enlist for a different MOS. Sometimes this can change your whole outlook on the service you are in.)

You cannot re-enlist for another service. All you can do is work with a recruiter from the service you seek to serve in and hope they have a slot when you separate. Thank you for your service.

Try the Coast Guard a friend of mine was Army aircrew wanted a change and went C G they took him he had to drop a rank he was a Sgt they dropped him to PO 3 which is e-4 but he should get his PO 2 within a year

E.g., flight interests, specific technical hardware exposure, seeking to aim for senior enlisted, warrant, commissioned...what are your basic fundamental goals? What are you seeking to ultimately accomplish through all your efforts?

It'd obv help a good deal to know more about your background, assocs, Bach, coursework esp STEM stuff, grades, GPAs, actual course titles, what specific AFSCs or naval rates you'd want to try for...I tried looking into going NFO for Macy, I did the aeromed exam, I was never able to intersvc, so, that being said, the mere wish to see that side of existence, without more exact info as to tour hobbies, interests, reading, sports incl any martial arts and ;most particularly, specific ambitions and/or motivations hardly gives any of us any really concrete idea of your fundamental aspirations...I'm not saying don't try, I'm merely saying us knowing more might help all of us try to help you, with specific, concrete suggestions, going into one svc is rough enough leapfrogging willy nilly from one to another with no concrete plan, or explicit idea in advance, to my way of thinking, is, at the very least, major premature, seemingly, placing the cart way before the horse...so, that being said, indulge a suggeston here genuinely intended to help, and give us all some really comcrete notion of tour turn of mind, so far as you can elaborate on it, if at all possible, OK?

Short answer is talk to that branch recruiter.
Why do you want to change branches though?

SPC (Join to see) talk to a recruiter from that branch. It's like you are walking in off the street. In AR601-210 it mentions having to wait 93 days...don't know why. Get your info from the recruiter.