“有自己的想法和主张”用英语怎么说？

have one's own ideas and opinions

其中，one's 是用来替代“my, your ,his ,her”等的形容词性物主代词的。如；
I have my own ideas and opinions.
He has his own ideas and opinions.

have one's own opinion

have one’s own idea/thought…… and opinions/viewpoint……