> how does light get reflected?

Photons ("packets of light") bounce off of particles (atoms, molecules).

> does it get reflected in all directions or in the direction where it came?

Keep in mind, if it only reflected back in the same direction, you'd never see anything that is opaque because all of the light emitted from a source (lamp, sun) would bounce right back to that source rather than your eyes. The fact that you can see your wall when you turn a lamp on tells you that light doesn't just bounce right back at the lamp.

It gets reflected the same as anything. Just like when you hit a pool ball. You have to remember that "light" is not a single photon (or beam) following one path though. Even a laser... you can see the dot is a couple of millimeters wide. Many atoms can fit in a couple of millimeters which means when you shine the laser at a material, some of the photons will hit spots where there is an atom, but others won't. In this way, even if they all follow the same rules about bouncing, some will bounce and others won't.

Think of it like dropping 10 balls side-by-side into the top of a Pinball machine. We cannot generally say "all balls will do X" since they're all in different positions and may hit different obstacles in the pinball machine. But we can say that in one pinball machine all the balls pass right through because there is no barrier, in another they jumble up a lot because there are many barriers and in yet another they just get stuck because there are too many barriers.

In the same sense, different materials (mirrors, glass, bricks, air) will tend to bounce stuff in certain ways based on the way their atoms are positioned. If the bouncing tends to happen in a way where two photons that are close to each other on the way in are also next to each other on the way out, you'll get something that looks like a mirror, but if the structure leads to bouncing where photons that started near each other will exit in different directions then it might look more like a brick. Photons also come in different "sizes" based on their color. So, if you shine a white light (white is made up of all the colors) some photons might bounce back at you but others might not. For example, with a brick, the red photons will bounce back at you, but the blue will mostly not. So, it looks reddish.

So, while the rules of light bouncing are pretty simple and similar to how you see anything bounce, the fact that "light" is usually many beams of photons and the objects you're shining them are are piles of atoms with huge gaps in between means that really complex effects can happen where millions of different bounces are occurring for different parts of the beam or even different colors of light and that creates all these different effects we see.

> does light gets weaker everytime it gets reflected i mean does the reflection gets weaker even time it also reflects?

It tends to, but it doesn't have to. What a "weaker" reflection means is that less photons hit your eyes. Given that each time a beam of light reflects again, there is some chance it will scatter a bit, that tends to mean that as it reflects more and more, there will be less photons hitting your eye.