Start with the foundation...
Build your business rep by building a couple of sites and get them to the highest position you can, as social proof.
Then, do the same for a few clients for cheap to get your foot in the door with actual testimonials of ' paid ' clients.
The most important thing is to build your experience and knowledge. If you don't have that covered, then don't bother, as you'd be wasting your time if you don't know what you are doing and what works. Furthermore, you shouldn't be offering services if you don't know what really works versus theory that you've simply read about in a guru program...which, just for your info - 99% of that stuff doesn't work and isn't ' SEO ' but, merely a marketing technique/tactic. Be clear on which you have and make sure it's what you actually need.
Bottom line here is to know your craft or it isn't ' your ' craft.
Best of luck with it.