Good day to everyone

First of all i have to mention that the acoustic guitar is considered a foreign instrument in my country . That means that there are no specialized guitar shops or expert luthiers around . So I will have to rely on my own and your valuable advice.

To the point , I have a Rogue RA-090 (cheap guitar ) , I have restrung the guitar with lighter gauge (Personal preference) after my G string broke and from what i read i think i made the mistake of removing all the guitar strings at once which changed the tension on the neck ?? My strings started to buzz slightly from open string to the 5-6 fret . I read that i should adjust my truss rod to fix this . But it seems a bit dangerous to the guitar with no expertise and foolish to do on a whim. So i took a few pictures to maybe help you help me solve the issue . I used a technique i found online to measure the relieve on the guitar ( capo 1st fret , finger on low E closest fret to the body) this pictures are of the middle fret (before and after pressing on the string)

I can't tell you how much the space , in the second picture , is exactly since i don't have a feeler gauge but i can fit at 0.010 inch string easily so it's more than 0.010 inch

I hope these information help you get an idea about the situation and Thanks in advance for any help you provide
That looks like pretty good action for easy playing. Moving to lighter strings could indeed require a truss adjustment for a hair more relief and lift at the nut. 1/4 counter clockwise (loosen, more curve) turn should be all it needs, wait a day for it to settle in before doing more if you think it needs it. This will also raise the action everywhere along the fretboard so you want to adjust as little as possible.
Changing the neck tension by removing all the strings won't hurt a thing. If the neck relief looks good, you might try raising the bridge a hair. To check neck relief, a business card is .012", about the maximum neck relief you want.

Cut a sliver out of a business card and put it under the bridge saddle. That will raise the strings slightly, shouldn't be enough to make the action too high. If you can get some thin plastic, that would work better. No more than .010", that's probably all you need. If not, go to .015". Standard notebook paper is about .003 to .005", the cardboard on a note pad .025".

I'm a former machinist, I still have micrometers and calipers to measure all this stuff, that makes it easier for me to find something that will work. I keep my calipers handy for measuring this stuff. I forget which guitar pick is just right for neck relief, it's not one of the Jim Dunlop Tortex ones I have sitting here for practice though...all too thick. Maybe a Fender Medium, I don't have one handy to check.
Hmmm...I wonder what this button does...
If I need to raise the saddle (boy, is that rare!) I use brass shims. Absolutely no harm to the tone, volume or sustain. I use a brass bridge and 6 individually adjustable saddles on my Silvertone archtop and it's just wonderful.