How to select a client in a project?

Select the client from your "My Contacts" directory. 

If the client is not yet added to the directory, you can always add a new client from here, and add other details like gst number, etc in My Contacts later.

 

You can change the client in the project anytime you want. 

Changing Client Name will change client name everywhere in the project like Estimate, Invoices , etc.