How to generate leads for freelancing?

Hi wise people

Can you guide me on how to generate leads for freelancing? Let's say i know java and I already have a profile on fiverr, portfolio website, github and some certification to back up my credentials.

But all i have is one client that too is there to ask for job support, so no quality work and no way to get more clients from them.

I have tried upwork but I am yet to get shortlisted on any of the projects.

So what other way can I reach out to people whom I can help? Through linkedin? Cold emailing?

If linkedin, then please guide me on how?

If it's a cold e-mail, then how do you even get whom to email? How to target or get email ids of these people? Crunchbase? For us based start up

Please help 🙏