Edilia, my corrections and changes to your text are shown below:
Well, well, well! There was I sitting down heavily on an old chair in a cold room waiting for my turn. I knew it was very early but I preferred to arrive early than show up later. I waited for about 2 hours. I was freezing and very uncomfortable. But “it’s for a good cause” I thought.
Later on, a short man with a smiling face wearing a black jacket came into the room. Well, “I’m not alone”, I wondered. So, as the time went by, I found myself with at least fifteen people. “Are all those people for interview?” I asked to myself. Maybe!
The room was full and very quiet. There were people all over: playing, sending / texting the messages and listening to music on their mobile phones. The other ones were just looking, very thoughtful, (like me) at the degraded false ceiling.
It was raining outside! I just could see through the small window people coming in and came out.
Suddenly a slim man who was dressed in green clothes came into the room and told us “you lot come along with me”. I was I bit nervous. “Now is the time for the truth, or maybe, to the action” I thought
In line, we walked through a long corridor to another small room again. There, they took our passports and NIN. After that, a lady with blond hair came into the room holding many papers on her arms. “What could it be”? I thought. She started to distributing them to us!
“Oh dear”! I mumbled! “It is the literacy and numeracy test” I couldn’t believe that! “For that kind of job they need a numeracy and literacy test”! I thought. Well, I could understand very well, why the company was been doing that! They couldn’t risk having people that don’t understand English, so if something went wrong, it could cost them a lot of money for them!
The test was very easy, even so, some people failed and they couldn’t pass to the next stage of the interview. Beside me there was a man of about fifty-five years old. I could see that he did nothing, but I couldn’t help him, (so the lady with blond hair was in front of us). I felt very sorry about him. He looked too worried and tired. His smiling face grew serious, and he failed the test.