My first janaza prayer

Assalamu alaykum wa rahmatullahi wa barakatuh.
Today I was in a very emotional mood and crying about random things. I had planned to go to university with a sister to pray jumu’ah there and had to meet her at the train station. But first I went to my Arabic teacher for a lesson and her nice naseehah ma sha Allah. Time flew while I was listening to her and out of shyness I couldn’t interrupt her to tell her that I had to leave. When she realized that we were well over time I had already missed the train. I was feeling very guilty for letting my friend go on her own but there was nothing that I could do about it at that point. So I went and took the next train that went to another place that has a big masjid.
I had never been at that masjid and so was taken by surprise when I saw how packed it was subhanAllah. The khutba was about raising pious children and parents’ mistakes in the process. Little did I know that a young brother aged 20 (just like me) was shot dead and we would be offering the funeral prayers for him. So I was sitting and wondering while all these old aunties were staying where they were while the khutba was being translating. Then the imam announced that we would pray janaza and everybody stood up. OH OH!
I had wanted to attend a janaza for quite a long time but never had the chance. To be honest I hadn’t even learned the ad’iyah to be recited. And here I was standing to pray janaza at a mosque where I hadn’t planned to be.. so unexpectedly. Just like death. I will leave out the details about my state during the prayer :p you can just imagine me there: packed masjid, emotional mood, unexpected situation..
I don’t know what to say.. right after leaving the masjid I had to teach English so I had to change my focus again. It was also a pity that I didn’t know what dua to recite so I just kept saying “Allahumma ghfir li akhina” and I don’t even know if that’s correct Arabic :$ but it certainly was a good reminder.. especially since I hadn’t expected to find myself praying at that masjid today let alone witness a janaza subhanAllah.
Also the fact that he was only 20 years old.. death can come any time. Seeing his mother and many other people cry.. I was just looking at it as an outsider but it’s a crazy thought that this was their reality.
May Allah wake our hearts up before it’s too late..