Currently on H4 visa and Valid h1B petition

Hello,

I am on H4 visa, extension applied but I have valid H1B petition . I want to start working to start working I do need to file COS.

But employer asking to find a project first. Is it valid (correct) process to find project first and file COS with premimum.

1>What if client is not ready to wait?

2>Can I work for some time without get paid?

What is correct procedure.

When applying for COS, it is possible USCIS asks for client information to be sure that employer will pay you.

Even if USCIS doesn’t ask for it and COS is approved, employer needs to pay you from Day 1 irrespective of whether you are working for a client or not.

So I can understand where employer is coming from and why he is insisting on getting a client first before applying for COS.