中文部分：
在图书馆意外碰到一个朋友,聊得很开心.朋友说的一句话让我印象很深刻,他说learning就好像播撒种子,虽然不是每颗种子都能收获.但是learning的越多,播种的就越多,收获的可能性也就越大.
你的翻译：语法和表达上都有几个错处,以下是我给你的更正.
I met a friend in (要加 the / a) library accidentally. We have a good conversation and one of his words leave(left是过去式) me (a impressive 要改为 with a deep/ strong impression), he said sometimes learning is like seeding, not every seed could (let you get要改为 germinate 萌芽), but if you keep learning just like you keep seeding, the more change(应该是chance 罢) you could get(要换上succeed).
很希望会对你有帮助.