I have a younger friend that I want to use these kind of expressions with, but don't know how to say it in Japanese. I want them to do their best and not have people take advantage of them. I feel they might be the kind of person, that would take negative things from other people to their detriment. So, I want to say something like, you have to stand up for yourself sometimes. If you don't people will take advantage of you. Any ideas?
You have to stand up for yourself sometimes. If you don't, people will take advantage of you.
You should stand up for yourself and not have people take advantage of you.