as im a complete newbie on everything here i would like to show my work(i dont even know if i should call this work)
so on this first image i would like to know if each battery has 1.5v am i gettin 9v? and the green string its positive one? or i should use the black and the red string on the side of those things?(im not using this batteries its just a test) also the batteries on the middle thing gets really hot ... it looks like only them are being used cuz the others dont change the temperature

i think its everything fine here...

this thing also gets really hot..i cant even touch...it should be like this?

No. The hot batteries probably indicate a short circuit (connecting positive straight to negative), and you're probably doing something wrong to the regulator if it's getting that hot.
That soldering job is atrocious.
Why would you use AA's an a portable 64 anyway?

yeah i just realized the problem... i have to use the wires on the side of that thing
im not using AA its just a test and that was the first time i used a soldering iron hahah

oh and i have done everything again so i think its better now

ok so i have rewired everything and now all the batteries are getting really hot...one of them even melted the battery case lol hmm i dont know maybe there is a problem on the step down regulator? cuz the only thing i can see connecting the positive to the negative its on the battery wires to make in in serie(?)

Make sure no metal is touching another piece of metal that it shouldn't be.