Hey, I just bought an acoustic guitar for 50 bucks, with the hard case and a dozen picks. It's called an Ensenada, the model is FG-43.

Unfortunately, the end of the soundhole to the bridge is concave, while under the bridge bellies. It's not huge, but it's obvious if you look close. I looked inside and it has a loose bracing right behind the soundhole, on the front. It's not x braced or whatever, it's a straight line. The bracing is obviously loose, the left side is not connected and is hanging a bit.

I loosened the strings more and haven't played it, was this the correct thing to do?
Can I glue it myself, or take it to a shop? there's also a hairline crack on the bridge connecting the pins. The neck isn't cracked and there are no other issues with it, I looked it over multiple times. Does this sound worth fixing? I don't want to pay a shish ton of money to fix it or get a whole new one. I just want an ok acoustic to take around cuz I've been playing electric for 3 years!

I've done both those repairs myself, on different guitars. For the loose brace I made an screw-expanding post like an Acrow prop that could be jammed between the brace and the back of the guitar to hold it in place, but you might be able to use a clamp. I glued it with PVA pushed into the joint with an artists pallet knife. It has been holding firm for about 15 years now.

The split bridge was a bit more complicated. Just gluing it might not work, because it is a high-stress point. I drilled holes across the width of the bridge and pinned it with dowels made of bamboo skewers. Drilling the holes was tricky. I attached the drill bit to a bamboo skewer with a piece of brass tube that was the right size, then drilled from the back of the guitar with a hand drill. I masked up the area between the drill and the bridge to prevent damage, and used guides, including my wife, to keep the drill bit in the right position. It is still holding fine after about 15 years,and the repair is invisible unless you look very carefully. at the back of the bridge.
It's a shop job, and I can't tell you what it would cost. This is a '70's off-brand guitar that really doesn't have a lot of value (there's the same model sitting at a Goodwill for the same price), but it's certainly worth getting an estimate. FWIW, I bought a brand new Yamaha for under $150 with the same kind of use in mind (you know, those Kumbaya moments on some sandbar around a bonfire), so you'll want to keep the costs down.
^^^^ I see this kind of repair as a good opportunity for honing one's workshop skills. If it works, you have reason to be proud and the guitar has acquired something of you - mojo if you like. If it doesn't, no big deal. - For example, I'm looking a junker acoustic to try my instant neck reset method. It worked on a nylon string, now I want to try it on something with a truss rod.
^^^^I see this a bit like working on a junker car. I *have* no skills, and while I'd certainly be proud of having done the work and while the car would certainly acquire something of me (it's usually blood and a bit of skin and some new vocabulary), there are better uses of my time (as the spousal unit is constantly reminding me). It's off to the shop!
Thank you very much! I did glue the bracing to the top and held it with a clamp because it was directly under the sound hole. I strung it back up the next day and it's playing amazing.
I think I will do what you recommended with the bridge when I have time, I don't believe it's causing issues right now.
The more I play it the more I like it, thank you for the tips!
I'm glad it worked out. I wouldn't leave the bridge too long, the crack can only get worse, not better. A couple of dowel should do the trick, between the 2nd and 3rd, and 4th and 5th pins. I would use epoxy for that, and then allow superglue to seep into the crack itself via the pin holes and top of the bridge to act as filler.