Quite accidentally I came across with my acquaintance with whom I have been standing in the same school and who was older than me approximately in 5 years. (?)

He doesn't know that guy's age and only assumes his age. It sounds like about 4-5 years older.

There, I ran into a guy who went to the same school and who was 4 or 5 years older than me.

Perfect! My question is this. Did he go to school with him before or are they classmates now?

👍Обычно говорят «учился со мной в (одной) школе. Возможно, наш товарищ мыслит немного по-английски.

That makes sense, Grumbler, thank you 🙏

Если речь о настоящем (недавней встрече), то "учился" означает в прошлом.
В отличие от английского, в русском времена глаголов не согласуют. Если now, то "втретил друга, который учится со мной..."

Если же встреча в прошлом, то возможны оба варианта.

Уточнил

+++Tatiana: BY SHEER COINCIDENCE, I ran into THIS guy THERE who HAD GONE to the same school AS ME and who was FOUR or FIVE years older than me/MY SENIOR. 👍🏼

Ага, про this guy подумала, но как видишь…)
The Past Perfect - конечно!
Спасибо за исправления!🤩🙏👍

Anytime, mami, post it!)))

Добавь сам, пожалуйста!🙏

Uly, why HAD GONE? Can we say this/
I ran into this guy there who used to go to the same school as me.
If yes, how does it change the meaning?

Uly?

You can say it that way too.

Good to know, thanks!