I can assure you that you cannot get clients without having some sort of a portfolio. Your first portfolio will be your own home. My very first client was a friend who loved my own home. When I told her that I was thinking about starting my business she let me know that she wanted to be my first client.
Let your home be the beginning of your portfolio. Style spaces in your home, take some really great pictures & put them on a file on your computer. Full rooms, vignettes, detailed shots...don’t make it complicated. Next, move on to your friends & family. Ask around if you can use their homes to style different spaces or vignettes. They don’t have to buy new things, just use what they have & put your spin on it.
Take good photos. You don't have to hire a professional photographer for the job. Your cell phone is more than enough to start your portfolio. As you grow, you'll want to hire this out or invest in a good quality camera.
Add the photos you take to your website...that I hope you are building, but if you aren't there yet, then start saving them somewhere on your computer. Add them to your social media accounts & see if you get any feedback.
Using your own home is the easiest & cheapest way to grow your portfolio.