Ask HN: Looking to start freelancing

So unfortunately the web development company I was working for downsized and laid me off. It had nothing to do with my performance, I'm a competent developer and hard-worker. Currently, I think freelancing may be a good route to try.

My questions regarding this are pretty straight forward.

1) I know I'm lacking a portfolio. This seems to be a chicken before the egg situation. How should I build a portfolio? Should I just make websites with no business behind them? How can I monetize an SAAS in a short time? I even struggle to think of an idea of a service to offer and get slightly discouraged to look out there and see almost every service covered.

2) How to market. I know freelancing is mostly about the hustle. But all the sites I look into either have people willing to work for $3-$8/hour or require a "professional" certification process requiring a portfolio as well as an interview and selection process. How can I compete and win the gig?

3) Time. I have a severance but it will run out eventually. I have savings but in all actuality how long would it take to build a service that brings in say, $100,000 yearly? That seems like a lot to ask for, but self-employment taxes are insane and living in America isn't cheap.

Any help you guys can offer would be great. I love the discussions here and am a regular reader. I also love software development and I never have had a day where I woke up and didn't want to do my job. I have a true drive and passion for this and I would regret every day if I was forced to leave it behind.

Thanks for your answers in advance.