It you build it, they will come. Maybe. If you build it right. And there's a lot that goes into building a law firm website "right": SEO, graphics, mobile-friendly layout, content, conversion optimization, and a whole lot more.
But don't jump off that building yet. Just like those with DIY motivation can learn to tile a bathroom floor, those who want to create their own websites can do so, and you don't even need to know code. But you will need some tools. And a whole lot of time and motivation.
Let's start with those tools: