Hi!
I am looking casting director or agency.
Do you guys know any?
Any tips and suggestions you want to share?

I would just search google for that

If you have no acting credit, then the only Agency that wants you is out to take your money by charging you for head shots, etc.
You need to start working without any representation.  When you have some great work under your belt, you will be able to pick the agency that you feel will represent you the best.