My life path is also long, I believed that later will meet a sincerity boy。

汗...别告诉我life path是指生命的道路啊？要不然我还以为是安全通道。
其实生命的道路随便用个life就好了，要不然你说the path of my life也好啊，千万别说life path，外国人见到会以为是专门用来逃生用的。

The path of my life is still long, I believe that I will meet a sincere boy later.
或者
I am still young, I believe that I will meet a sincere boy later.
或者
My life still has a long way to go (through), I believe that I will meet a sincere boy later.
later 可以换成in the future比较好

中文是想说
我生命的道路还有很长， 我相信将来我会遇到一个真诚的男孩的。