It's funny because I have been for 10 years in a relationship and I didn't exactly know what I wanted, we were just with each other without plans. But since my separation I know I want kids and somebody who is financially and emotionally stable, and with whom I can communicate easily, that was missing in my last relationship. He would not listen, will brush it off or would lie. I want trust.
For online dating I would say like in real life to know what you are looking for and to be aware of your choice. In life we can't be sure of anything, you have nothing to lose by trying anyway.
Good luck