Tough question. Everyone and their brother can claim to be a WordPress developer, so the competition is indeed brutal. You aren't going to be able to compete on price, so what can you bring to the table that thousands of overseas/freelance developers can't? Are you a graphic designer? Do you manage projects well? Are you a good people person? Are you passionate about the work? Do you have a large network of contacts who may be able to refer business to you? Do you know SEO? You really need to find something that would make you stand out from the crowd or offer some advantage that others don't have.
There are lots of sites like upwork.com and freelancer.com where you can bid on projects, but again, you are going up against guys who charge $5/hr so that is going to be tough.
Getting yourself on Google for search terms like 'wordpress developer' will also be nearly impossible, so you are really going to have to rely on referrals and networking. You'd be surprised by how much work you can get from doing a great job on just one web site. I started from scratch with my business, and one job for a well-known company has led to hundreds of projects. So really you are going to have to make your work speak for itself - building something that is just 'ok' won't do it - you need to really kick ass!
As far as WooCommerce goes, you need to have a firm grasp of all of the nuances of e-commerce if you are going to go down that road. Do you fully understand PCI compliance? Payment Gateways? Shipping logistics? SSL certificates? Tax laws? SEO? Providing front-end development is a WHOLE different ballgame than providing an e-commerce site for a client. Be sure that you know exactly what you are doing if you are going to offer that as a service. If your client's site gets hacked due to your negligence and credit card data is stolen, you are in a world of trouble. And since WordPress is the most hacked platform on the planet, this is a very real concern. Installing WordPress and WooCommerce on a cheap GoDaddy hosting plan and calling it a day just isn't going to cut it.
So find your niche, build high-quality sites, make the client happy and stay on top of the latest trends/tech and you can have a shot of making it in this business. Will it be easy? Definitely not, but certainly worth a try if is something you are passionate about. If you are just looking to make a few bucks because you don't have any other options, this probably isn't the right path for you.